Comparison
Writing balanced chemical equations:
Identify the reactants and products of the reaction. In a word equation, the reactants and products are described using their common names. For example, in the reaction between hydrogen and oxygen to form water, the reactants are hydrogen and oxygen, and the product is water.
Convert the common names of the reactants and products into their chemical formulas. For example, hydrogen is H2, oxygen is O2, and water is H2O.
Write the chemical formula equation for the reaction. In a chemical formula equation, the reactants are written on the left side of the arrow and the products are written on the right side of the arrow. The arrow represents the transformation of reactants into products. For example, the chemical formula equation for the reaction between hydrogen and oxygen to form water is: H2 + O2 → H2O
Balance the equation by making sure that the number of atoms of each element is the same on both sides of the arrow. To balance an equation, you may need to adjust the coefficients (numbers written in front of the chemical formula) of the reactants and products. For example, the balanced chemical formula equation for the reaction between hydrogen and oxygen to form water is 2H2 + O2 → 2H2O
Determine the states of matter of reactants and products. The state of matter can be determined by looking at the conditions of the reaction and the chemical properties of the elements involved. The states of matter include solid, liquid, gas, and aqueous (dissolved in water). For example, hydrogen and oxygen are gases in their standard states, and water is a liquid. The chemical equation should include the state of matter of reactants and products. For example, the chemical equation for the reaction between hydrogen and oxygen to form water can be written as: 2H2(g) + O2(g) -> 2H2O(l)
Net ionic Equations:
A net ionic equation is a chemical equation that shows only the species that are directly involved in a chemical reaction. It represents the simplified form of a balanced equation by omitting spectator ions, which are ions that do not participate in the reaction and remain unchanged.
How to write Net ionic Equations:
Chart of solubles
A solubility chart is a table that lists the solubility of different compounds in water at a given temperature. It can be used to predict the products of a double displacement (also known as a metathesis) reaction, in which the positive ion of one reactant is exchanged with the positive ion of another reactant.
How to use chart:
To use a solubility chart to predict the products of a double displacement reaction, you first need to identify the reactants in the reaction. For example, let's say the reactants are sodium chloride (NaCl) and silver nitrate (AgNO3). ^ Once you have identified the reactants, you can use the solubility chart to determine the solubility of the products in water. If a compound is listed as "soluble" on the chart, it means that it can dissolve in water. If a compound is listed as "insoluble", it means that it is not able to dissolve in water.
Naming From Written Name First
Ionic compounds: The chemical formula for an ionic compound can be determined by writing the chemical symbol for the cation (positive ion) first, followed by the chemical symbol for the anion (negative ion). The charge of the cation and anion must be balanced by the use of subscripts. For example, the name "sodium chloride" corresponds to the formula NaCl, where Na is the symbol for sodium and Cl is the symbol for chlorine.
Covalent compounds: The chemical formula for a covalent compound can be determined by writing the chemical symbol for each element in the compound. The number of atoms of each element is indicated by a subscript written after the symbol. For example, the name "carbon dioxide" corresponds to the formula CO2, where C is the symbol for carbon and O is the symbol for oxygen. In a covalent bond, the second element in the bond’s name would have a prefix regarding the number of that element (number as a subscript), such that the numbers correspond to its greek prefix; 1 = Mono, 2 = Di, 3 = Tri, 4 = Tetra, 5 = Penta, 6 = Hexa, 7 = Hepta, 8 = Octa, 9 = Ennea, 10 = Deca and such forth.
Molecular compounds: The chemical formula for a molecular compound can be determined by writing the chemical symbol for each element in the compound. The number of atoms of each element is indicated by a subscript written after the symbol. For example, the name "water" corresponds to the formula H2O, where H is the symbol for hydrogen and O is the symbol for oxygen.
In summary, to find the formula of a compound from its name, you can use the chemical symbols of the elements that compose it, the oxidation state of the elements, and subscripts to balance the charge of the ions in the case of ionic compounds.
Binary acids: These are acids that contain only hydrogen and one other element. The chemical formula for a binary acid can be determined by writing the chemical symbol for the nonmetal element, followed by the symbol for hydrogen (H), and a subscript indicating the number of hydrogen atoms present. For example, the name "hydrochloric acid" corresponds to the formula HCl, where H is the symbol for hydrogen and Cl is the symbol for chlorine.
Oxyacids: These are acids that contain hydrogen, oxygen, and another element. The chemical formula for an oxyacid can be determined by writing the chemical symbol for the nonmetal element, followed by the symbol for oxygen (O), the symbol for hydrogen (H) and subscripts indicating the number of atoms of each element present. For example, the name "nitric acid" corresponds to the formula HNO3, where H is the symbol for hydrogen, N is the symbol for Nitrogen and O is the symbol for oxygen.
How to name
Oxyacid variants: These are acids that contain hydrogen, oxygen, and another element, but the number of oxygen atoms is not specified. The chemical formula for an oxyacid variant can be determined by writing the chemical symbol for the nonmetal element, followed by the symbol for oxygen (O), the symbol for hydrogen (H) and subscripts indicating the number of atoms of each element present and prefixes indicating the presence of a lower or higher amount of oxygen atoms, respectively. For example, the name "sulphurous acid" corresponds to the formula H2SO3, where H is the symbol for hydrogen, S is the symbol for sulphur and O is the symbol for oxygen.
Lewis dot diagrams, also known as Lewis structures, are used to represent the valence electrons of an atom or molecule and can be used to determine the polarity of a molecule. Electronegativity is a measure of an atom's ability to attract electrons in a chemical bond. A molecule with a difference in electronegativity between atoms is polar and will have dipole-dipole or hydrogen bonding forces between its molecules.
VESPR diagrams:
The VSEPR theory states that electron pairs (both bonding and non-bonding) around a central atom in a molecule will arrange themselves to minimize repulsion and achieve a geometry that maximizes the distance between electron pairs. The VSEPR diagram is a visual representation of this arrangement.
How to Draw a VSPR diagram:
How to Draw Lewis Structures:
Lewis structure
Cation:
A cation is a positively charged ion. It is formed when an atom loses one or more electrons from its outermost shell. The loss of electrons creates a deficiency of negative charges, resulting in a net positive charge on the cation. Cations are typically formed from metal atoms.
Anion:
An anion is a negatively charged ion. It is formed when an atom gains one or more electrons, leading to an excess of negative charges and a net negative charge on the anion. Anions can be formed from nonmetal atoms or groups of atoms.
Naming compounds
creating balanced equations
Venn diagram
graphical relationships between the pression, volume, and temperature of a gas
Car Tire (Real life Example):
After driving, the air pressure in a car's tires goes up. This is because friction (a contact force) between the tires and road causes the air inside the tires to heat up. The air cannot expand because the tires are essentially a fixed-volume container, so the pressure increases
Combined Gas Law:
The combined gas law expresses the relationship between the pressure, volume, and absolute temperature of a fixed amount of gas.
Equation:
This law allows us to calculate the new pressure, volume, or temperature of a gas if the other two variables change, as long as the initial and final conditions are known.
(P₁V₁) / T₁ = (P₂V₂) / T₂
- P1 = initial Pressure
- V1 = Initial Volume
- T1 = initial Temp
- P2 = Final pressure
- V2 = Final Volume
- T2 = Final Temperature
The combined gas law is a gas law that combines Boyle's Law, Charles's Law, and Gay-Lussac's Law into a single equation. It allows for the calculation of the relationship between the pressure, volume, and temperature of a gas when all three variables are changing.
Real life example
When the amount of gas remains constant, but the pressure, volume, and temperature fluctuate, this rule applies. Cloud formation, refrigerators, and air conditioners
Comparison of Gay Lussacs Law and Charles Law
Grade 11 Chemistry
Unit 1: Gasses and Atmospheric Chemistry
Gas Laws:
There are 5 types of Gas Laws
- Charles Law
- Boyles Law
- Gay-Lussacs Law
- Ideal Gas
- Avogadro's Law
Charles Law:
Describes the relationship between the volume and temperature of a gas, assuming constant pressure. It states that the volume of a given amount of gas is directly proportional to its absolute temperature.
Equation:
V₁ / T₁ = V₂ / T₂
- V1 = Intial Volume
- T1 = intial Temperature (In kelvin)
- V2 = Final Volume
- T2 = Final Temperature
Example of Charles Law
Kelvin scale:
The Kelvin temperature scale is an absolute temperature scale that is widely used in scientific and engineering applications. It is named after the Scottish physicist William Thomson, also known as Lord Kelvin, who proposed this scale in the 19th century.
The Kelvin scale is defined in such a way that the size of one Kelvin degree (1 K) is equal to one Celsius degree (1 °C). Therefore, the Kelvin scale has the same magnitude as the Celsius scale, but it starts from absolute zero instead of the freezing point of water.
Absoloute Zero:
The Kelvin scale is based on the concept of absolute zero, which is the lowest possible temperature that can theoretically be achieved. Absolute zero corresponds to 0 Kelvin (0 K), or -273.15 degrees Celsius. At absolute zero, the particles of matter have minimal thermal energy and virtually no motion.
Conversion Of Kelvin to Celsius/ Celsius to Kelvin
Kelvin to Celsius
(Kelvin_T) - 273 = Celsius
Celsius to Kelvin
(Celsius_T) + 273 = Kelvin
Hot Air balloon:
Is a real life example of Charles law in use because in order to make a hot air balloon rise, heat is added to the air inside the balloon. Adding heat causes the molecules to move further away from each other
Hot Air balloon
Avogadro's Law:
states that equal volumes of gases, at the same temperature and pressure, contain an equal number of molecules. It describes the relationship between the volume and the amount (number of moles) of a gas.
Blowing Balloon
Avogadro's Law is in evidence whenever you blow up a balloon. The volume of the balloon increases as you add moles of gas to the balloon by blowing it up. If the container holding the gas is rigid rather than flexible, pressure can be substituted for volume in Avogadro's Law.
Diagram
Molar Volume:
Molar volume is the volume occupied by one mole of a gas at a specific temperature and pressure. At standard temperature and pressure (STP), the molar volume of a gas is 22.4 L/mol.
Problem using Molar Volume
According to Avogadro's Law, if the temperature and pressure of a gas are held constant, an increase in the number of moles of the gas will result in an increase in its volume, and vice versa. This law is based on the concept that gases consist of individual particles (atoms or molecules) that are in constant motion, and equal volumes of gases contain an equal number of these particles.
Gay Lussacs Law:
states that the pressure of a given amount of gas is directly proportional to its absolute temperature when the volume is held constant.
According to Gay-Lussac's Law, if the volume of a gas is held constant, increasing the temperature of the gas will result in an increase in its pressure, while decreasing the temperature will cause a decrease in pressure, assuming the amount of gas remains constant.
Example
Equation:
P₁ / T₁ = P₂ / T₂
- P1 = Initial Pressure
- T1 = Initial Temperature
- P2 = Final Pressure
- T2 = Final Temperature
Law in use
Boyles law:
is a fundamental gas law that describes the relationship between the pressure and volume of a gas at constant temperature. It states that the pressure of a given amount of gas is inversely proportional to its volume, when temperature is held constant.
According to Boyle's Law, if the temperature of a gas is kept constant, decreasing the volume of the gas will result in an increase in its pressure, and vice versa. In other words, when the volume of a gas decreases, the gas particles have less space to move, leading to more frequent collisions with the container walls and hence an increase in pressure. Conversely, when the volume of a gas increases, the gas particles have more space to move, resulting in fewer collisions and a decrease in pressure.
Equation
P₁V₁ = P₂V₂
- P1 = initial pressure
- P2 = final pressure
- V1 = Initial Volume
- V2 = Final Volume
Example soloution
Filling up tire pressure:
You can observe a real-life application of Boyle's Law when you fill your bike tires with air. When you pump air into a tire, the gas molecules inside the tire get compressed and packed closer together. This increases the pressure of the gas, and it starts to push against the walls of the tire
Ideal Gas Law:
- They are hypothetical gases that are
composed of particles:
With no size
Travel in straight lines
No attraction to each other
- We use them because the math is
easier!
Airbags:
The airbags in vehicles work on the ideal gas law. When the airbags are installed the different types of gases quickly fill in which inflates them. The nitrogen gas gets filled in the airbags due to a reaction between sodium azide and potassium nitrate.
Equation
Example Problem
The Mole:
- Things in chemistry is small and they dont have much mass.
- These "things" include molecules atoms and ions.
- There are 6.022x1023
Avogadro's number:
- In one mole of anything there is 6.02x1023 particles
- Atomic mass on the periodic table is the mole of one atoms of that subtance.
Molar Mass:
Kinetic Molecular Theory:
- Particles of matter are
ALWAYS in motion
- Volume of individual
particles is ≈ zero.
- Collisions of particles with
container walls cause the
pressure exerted by gas.
- Particles exert no forces
on each other.
- Average kinetic energy is
proportional to Kelvin
temperature of a gas.
Volume:
The volume of a gas is inversely proportional to the number of particles in the container. As the volume of a gas decreases, the number of collisions between the particles increases, and the pressure of the gas increases.
Temperature:
- Temperature is a measure of the average kinetic energy of the entities of a substance.
- So...as the particles move faster, the temperature increases.
- The kinetic energy of the particles in a gas is directly proportional to the temperature of the gas. As the temperature of a gas increases, the kinetic energy and the speed of the particles increase as well.
Pressure:
The pressure of a gas is directly proportional to the number of collisions between the particles and the walls of the container. As the pressure of a gas increases, the number of collisions increases, and the particles hit the walls of the container with more force.
The Gas State:
- Takes the shape and volume of the container
- Highly compressible
- Flows easily
-Gases are composed of large numbers of small particles that are in constant random motion.
Partial Pressure:
The pressure that one gas in a mixture
would exert if it were the only gas present
in the same container (i.e. same volume)
at the same temperature.
Daltons Law of Partial Pressure:
Dalton's law of partial pressures states that the total pressure of a mixture of gases is equal to the sum of the pressures that each gas would exert if it were present alone at the same temperature and volume. This means that the pressure exerted by a gas in a mixture is not affected by the presence of other gases.
Equation for Daltons law
Ptotal = P1 + P2 + P3....
P = Pressure
Example of Daltons law
Conversion factors for pressure
Unit#3: Quantities in Chemical Reactions
Molar mass:
Molar mass, also known as molecular weight, is the mass of one mole of a substance. It is expressed in grams per mole (g/mol). Molar mass is calculated by summing up the atomic masses of all the atoms in a molecule.
How to calculate:
To calculate the molar mass of a compound, you need to know the chemical formula and the atomic masses of the elements present. Multiply the atomic mass of each element by the number of atoms of that element in the compound, as indicated by the subscripts in the formula. Then, sum up the individual masses to obtain the molar mass of the compound.
Mole Ratio:
Is defined as the ratio of moles of one substance the moles of another substance in a balance equation
Mole ratio refers to the ratio of moles between two substances in a balanced chemical equation. It is based on the stoichiometry of the reaction, which describes the quantitative relationship between the reactants and products.
In a balanced chemical equation, the coefficients represent the mole ratios between the different substances involved. These coefficients indicate the relative number of moles of each substance required or produced in the reaction.
Empirical Formula:
The empirical formula of a chemical compound represents the simplest whole-number ratio of atoms of each element present in the compound. The molecular formula, on the other hand, represents the actual number of atoms of each element in a molecule of the compound.
How to determine Empirical formula:
Molecular formula:
The molecular formula represents the actual number of atoms of each element present in a molecule of a compound. It provides information about the composition and structure of the molecule.
The molecular formula is derived from the empirical formula, which gives the simplest whole-number ratio of the elements in a compound. The empirical formula does not provide the exact number of atoms present in the molecule.
How to determine Molecular Formula:
Word problem
Quantities and chemical reactions in real life:
Cooking: In the kitchen, chemical quantities and calculations are involved in measuring ingredients, following recipes, and adjusting quantities for desired results. This includes measuring volumes, weights, and converting between units for accurate ingredient proportions.
Pharmaceutical and Chemical Laboratories: Laboratories extensively use chemical quantities and calculations for research, development, and quality control. Precise measurements, dilutions, and conversions are critical for accurate experimentation, analysis, and production of pharmaceuticals and chemicals.
Water Treatment: Chemical quantities and calculations are vital in water treatment processes, such as disinfection and purification. Chemicals like chlorine or ozone are added in specific amounts to treat water, eliminate pathogens, and maintain safe drinking water standards.
The mole equation
n = n/m
where n is the number of moles of a substance, m is the mass of the substance, and M is the molar mass of the substance.
Nx = n x NA (Avogadro's number) - where Nx is the number of atoms or molecules of a substance, n is the number of moles of the substance, and NA is Avogadro's number.
m = n x M - where m is the mass of a substance, n is the number of moles of the substance, and M is the molar mass of the substance.
example problem
Limiting reagents:
is the reactant that we have more than enough of. There will still be some left in the reaction vessel. The reactant that is completely consumed in a chemical reaction, limiting the amount of product that can be formed. In a reaction, the amount of product formed is determined by the limiting reagent.
Excess reagents:
is the reactant that we have more than enough of. There will be some left in the reaction vessel.
The reactant that is not completely consumed in a chemical reaction, and remains in excess after the reaction is complete. The excess reagent does not affect the amount of product that can be formed.
Determining Limiting reagents:
You MUST compare the amounts using stoichiometry to see them at a 1:1 ratio... lowest number is our Limiting Reagent.
In a reaction between 2 moles of hydrogen gas (H2) and 1 mole of oxygen gas (O2) to form 2 moles of water (H2O), oxygen gas is the limiting reagent because it is completely consumed in the reaction and limits the amount of water that can be formed
Example problem
Theoretical yield:
the amount of product that can be formed by a chemical reaction, assuming that all the limiting reagent is consumed and all the reactants are in their stoichiometric ratio.
Percent yield:
The percent yield is a measure of the efficiency of a chemical reaction, representing the actual yield obtained as a percentage of the theoretical yield. It gives an indication of how much of the expected product was actually obtained in the reaction.
Actual Yield:
the amount of product that is actually formed in a chemical reaction.
Equations:
Theoretical yield:
Theoretical Yield = (Amount of limiting reactant given or used) x (Molar ratio to the desired product) x (Molar mass of the desired product)
Percent Yield:
Percent Yield = (Actual Yield / Theoretical Yield) x 100
How to find Theoretical yield
Identify the limiting reactant: Determine which reactant is the limiting reactant. The limiting reactant is the one that is completely consumed in the reaction and determines the maximum amount of product that can be formed. This can be determined by comparing the mole ratios of the reactants to their available amounts or by calculating the moles of each reactant.
Determine the stoichiometry: Use the coefficients from the balanced equation to determine the mole ratios between the limiting reactant and the desired product. This ratio allows you to calculate the moles of the product that can be obtained from the limiting reactant.
Convert moles to mass: Convert the moles of the product obtained from step 3 to mass using the molar mass of the desired product. The molar mass is the mass of one mole of the substance and can be found by summing the atomic masses of the atoms in the chemical formula.
Applications of Limiting Reagents:
Reduce costs for Manufacturing - do the math, make sure that you don't use too much of an expensive material
Reduce Environmental impact - ensure there is excess oxygen when using combustion reactions.
Percent composition: a way to express the relative abundance of the elements in a compound. It is the percentage of each element in a compound, based on the total mass of the compound. It can be calculated by dividing the mass of each element in the compound by the total mass of the compound and then multiplying by 100%.
Law of Definite proportions:
states that the elements in a compound are always present in fixed and definite proportions by mass. This means that regardless of the source or method of synthesis, a particular compound will always contain the same elements in the same proportions by mass. The percentage composition of a compound can be used to determine these fixed and definite proportions.
Calculating Percentage Composition:
For example, let's say we have a compound made up of 10 grams of carbon, 8 grams of hydrogen, and 2 grams of oxygen. To calculate the percentage composition of carbon in this compound, we would divide the mass of carbon (10 grams) by the total mass of the compound (10 + 8 + 2 = 20 grams), which is 0.5. Then we would multiply by 100% to get the percentage composition of carbon in the compound, which is 50%.
Example problems
Can be determined in a lab, which allows you to determine the formula for a compound.
Unit 2: Matter Trends and Bonding
Periodic Table and trends
Dmitri Mendeleev:
- Mendeleev set out to identify a pattern in the
elements.
- Mendeleev looked at many pieces of evidence and made an important observation that some elements have similar chemical and physical properties.
- Mendeleev then embarked on the tedious task of organizing all known information for every element to help him decipher the hidden pattern.
Early Periodic Table:
To begin his task, Mendeleev wrote facts about the elements on individual paper cards.
On these cards, Mendeleev wrote information such as the elements' melting points, densities, colors, atomic masses and bonding powers.
How he organized the table
Mendeleev noticed that patterns appeared when the elements
were arranged in order of increasing atomic mass.
As he laid out cards, each element had properties similar to the
elements above and below it.
Mendeleev's table was not perfect, however. Arranging the
elements by increasing atomic mass left three blank spaces in
the table.
Modern Periodic table
Valence electrons:
Valence electrons are the electrons in the outermost shell of an atom. As you move from left to right across a period in the periodic table, the number of valence electrons generally increases. This is because as the atomic number increases, the number of electrons in the outermost shell also increases. Conversely, as you move down a group in the periodic table, the number of valence electrons generally decreases. This is because as the atomic number increases, the number of electron shells also increases, which causes the outermost shell to be farther away from the nucleus and therefore have fewer electrons
Electron Configuration:
Electron configuration refers to the distribution or arrangement of electrons within an atom or ion. It describes the specific energy levels (shells), sublevels (orbitals), and the number of electrons in each sublevel.
Quantum Numbers:
A set of 4 numbers that describe various properties of an orbital. They are solutions to Schrodinger's Wave equation.
These numbers are like addresses to find the position of electrons in an atom
Aufbau principle:
The Aufbau principle tells us when building energy diagrams we always start at the lowest energy level and build up.
Aufbau pyramid
The principle number
The symbol n, is used to label the energy level
The secondary Quantum number (lower case l):
- Describes additional electron energy sublevels or subshells that form part of the main energy level.
- and the shape of the orbital
- each orbital has its own energy level
- "s" orbitals are lower in energy than "p" orbitals and so on.
Chart of Energy levels
Table of the values
The magnetic Quantum numbers, ml
- Tells us the direction of the electron orbit
- it ranges from +l and -l (tells us the # of orientations of orbits possible).
- hunds tells us we have half orbitals before we can completely fill them
The spin quantum number ms
The Pauli exclusion principle states:
in a given atom no two electrons can have the same set of 4 QN (n, l, ml, and ms)
When 2 e- share and orbital they always go in opposite directions.
The value of ms can only be - 1/2 or + 1/2
Energy levels on the periodic table
The electron configuration of an atom is based on the Aufbau principle, which states that electrons occupy the lowest available energy levels before filling higher energy levels. Additionally, the Pauli exclusion principle dictates that each orbital can hold a maximum of two electrons with opposite spins (up and down).
Valance electron
Electronegativity: Electronegativity refers to an atom's ability to attract electrons. As you move from left to right across a period in the periodic table, the electronegativity generally increases. This is because as the atomic number increases, the number of protons in the nucleus also increases, making the atom more positively charged and therefore more able to attract electrons. Conversely, as you move down a group in the periodic table, the electronegativity generally decreases.
if EN = 0 - 0.5 (non-polar)
EN = 0.5 - 1.7 (polar, covalent)
EN = 1.7 (ionic bond)
Atomic Mass:
Atomic mass, also known as atomic weight, refers to the average mass of an atom of an element. It is a measure of the mass of the protons, neutrons, and electrons within an atom.
The atomic mass of an element is typically represented in atomic mass units (amu)
The atomic size refers to the physical size of an atom. As you move from left to right across a period (row) in the periodic table, the atomic size generally decreases. This is because as the atomic number (the number of protons) increases, the number of protons in the nucleus also increases. However, the number of electrons in the outermost shell remains the same, causing the positively charged protons to pull the negatively charged electrons closer to the nucleus, resulting in a smaller atomic size. Conversely, as you move down a group (column) in the periodic table, the atomic size generally increases. This is because as the atomic number increases, the number of electrons in the outermost shell also increases, causing the electrons to be farther away from the nucleus, resulting in a larger atomic size
Average Atomic mass:
Is the weighted average of all of the naturally occuring isotopes of the element.
Since different isotopes of an element have different numbers of neutrons, they have slightly different masses. The average atomic mass considers the contribution of each isotope based on its abundance in nature.
Equation:
(mass of isotope) x (decimal abundance)
The calculation of average atomic mass involves multiplying the mass of each isotope by its relative abundance, expressed as a decimal fraction, and then summing up these values. The resulting sum represents the average mass of all the isotopes of the element.
Electron Affinity:
The energy change associated with
adding an electron to a gaseous
atom
Most of the time, the energy change is the
release of energy, making EA values negative
Easiest to add to halogens
. Addition of an electron to halogen completes the octet rule
Trends in Electron Affinity
EA increases from left to right
in a period (atoms become smaller, with greater nuclear charge)
EA decreases down a group, as clearly seen in Group 1, but this may not be the case for other groups.
Mass spectrometer
Negative E.A
A negative E.A. value means that the atom
becomes more stable and thus releases a
great deal of energy when it gains an
electron.
Positive E.A
A positive E.A. value means that the atom
becomes less stable and thus gains
energy when it gains an electron.
Ionization Energy:
Ionization energy refers to the amount of energy required to remove an electron from an atom. As you move from left to right across a period in the periodic table, the ionization energy generally increases. This is because as the atomic number increases, the number of protons in the nucleus also increases, making it more difficult to remove an electron from the atom due to the increased positive charge in the nucleus
Graph
Conversely, as you move down a group in the periodic table, the ionization energy generally decreases. This is because as the atomic number increases, the number of electrons in the outermost shell also increases, making it easier to remove an electron from the atom due to the increased distance between the electrons in the outermost shell and the nucleus.
Ionic compounds:
are composed of positively and negatively charged ions that are held together by electrostatic forces of attraction. These compounds are formed when one or more electrons are transferred from a metal atom to a nonmetal atom, creating ions with a net positive and negative charge. The resulting compound has a crystal lattice structure, and the ions are arranged in a repeating pattern.
Binary Ionic Compounds: Ionic compounds are composed of positive and negative ions. The name of the cation (positive ion) comes first, followed by the name of the anion (negative ion). For example, NaCl is named sodium chloride. The anion can have different prefixes such as "per-" indicating a high oxidation state, or "hypo-" indicating a lower oxidation state.
Polyatomic Ionic Compounds: These compounds are also composed of positive and negative ions, but the negative ion is polyatomic (a group of atoms that acts as a single ion). The name of the cation comes first, followed by the name of the polyatomic ion. For example, NH4Cl is named ammonium chloride.
Properties of Ionic Compounds:
- form crystal lattice structures
- they are hard and brittle
- relatively high melting and boiling points.
- they conduct electricity as molten liquids and when dissolved in water (not as solids)
Pesticides:
Pesticides are chemical substances or mixtures of chemicals used to control, repel, destroy, or mitigate pests. Pests can include insects, weeds, fungi, rodents, bacteria, viruses, and other organisms that can damage crops, harm livestock, spread diseases, or cause nuisance to humans.
Glyphosate:
Glyphosate is a broad-spectrum herbicide widely used in agriculture and gardening to control weeds. It inhibits an enzyme essential for the growth of plants, effectively killing unwanted vegetation.
Chemical Formula:
C3H8NO5P
Why is it bad?
Glyphosate can have adverse effects on the environment. It is a broad-spectrum herbicide that can harm non-target plants, leading to biodiversity loss and disrupting ecosystems.
Human Health issues:
There are concerns about potential human exposure to glyphosate residues. Glyphosate residues have been detected in food, water, and human urine samples. Although regulatory authorities generally deem glyphosate residues in food to be within safe limits, there are ongoing debates and studies on the long-term health effects of chronic low-level exposure.
Hydrates:
Hydrates are compounds that have a specific number of water molecules chemically bound to them. The name of the compound is written as the base name of the compound followed by a Greek prefix indicating the number of water molecules present and the word "hydrate". For example, CuSO4 * 5H2O is named copper(II) sulphate pentahydrate
Compounds with elements with multiple valences:
Elements can have multiple oxidation states, which are represented by a Roman numeral in the name of the compound. This numeral is written in parentheses and follows the name of the element. For example, FeCl2 is named iron(II) chloride, and FeCl3 is named iron(III) chloride.
Covalent Compounds
are composed of nonmetal atoms that are held together by covalent bonds, which involve the sharing of electrons between atoms. These compounds are formed by atoms sharing electrons to achieve stability by filling their outermost shell. The resulting compound can have a variety of structures, from simple molecules to large networks.
Binary Covalent Compounds: Covalent compounds are composed of nonmetal atoms that are held together by covalent bonds. The name of the first element comes first, followed by the name of the second element, with an -ide suffix. For example, CO2 is named carbon dioxide. Binary Acids: These are acids that contain only hydrogen and one other element. The name of the nonmetal element comes first, followed by the word "acid". If the acid contains hydrogen in the formula, the prefix "hydro-" is added before the name of the nonmetal element. For example, HCl is named hydrochloric acid.
Unit 3 Chemical Reactions
Decomposition:
A decomposition reaction, also known as a breakdown reaction, is a type of chemical reaction in which a single compound breaks down into two or more simpler substances. It is essentially the reverse of a synthesis reaction.
In a decomposition reaction, a compound is broken down into its constituent elements or smaller compounds.
What is it?
In a decomposition reaction, a single reactant breaks down into two or more products. For example, the reaction between water and sodium chloride forms hydrogen and chlorine (2H2O + 2NaCl -> 2H2 + Cl2).
General Formula:
AB --> A + B
where AB represents the reactant compound, and A and B are the products formed.
Single displacement:
A single displacement reaction, also known as a single replacement reaction or a substitution reaction, is a type of chemical reaction in which an element displaces or replaces another element in a compound. The reaction involves the transfer of an atom or an ion from one reactant to another.
What is it?
In a single displacement reaction, a more reactive element displaces a less reactive element from a compound. The activity series can be used to predict the products of a single displacement reaction. For example, zinc (Zn) is more reactive than copper (Cu), so zinc can displace copper from copper sulphate (Zn + CuSO4 -> ZnSO4 + Cu)
General Formula:
A + BC → AC + B
where A and B are elements, and BC is a compound. The element A displaces B from the compound BC, resulting in the formation of a new compound AC and a new element B.
The Activity Series:
The activity series is a list of elements in order of their relative reactivity. It is used to predict the products of single displacement reactions, where a more reactive element displaces a less reactive element from a compound.
Examples
About the Activity Series:
- In order for a reaction to occur the metal that is alone has to be higher up
- The further apart the elements are on the series the quicker the reaction will occur.
Double Displacement:
A double displacement reaction, also known as a double replacement reaction or a metathesis reaction, is a type of chemical reaction that involves the exchange of ions between two compounds. In this reaction, the positive ions (cation) and negative ions (anion) of two compounds switch places, resulting in the formation of two new compounds.
What is it?
In a double displacement reaction, also known as a double replacement reaction or a metathesis reaction, two compounds exchange ions with each other. The cation of one compound combines with the anion of the other compound, resulting in the formation of two new compounds.
General Formula:
AB + CD → AD + CB
where A, B, C, and D represent elements or groups of elements, and AB and CD are the two initial compounds. The cation from one compound combines with the anion from the other compound, forming two new compounds AD and CB.
The swtichers analogy
To determine if a double displacement reaction will occur, you need to consider the solubility rules and the formation of a precipitate, gas, or water as products.
What is a soluete:
A substance that is dissolved
Solvent:
A subance that the solute dissolved in
Solution:
A homogeneous mixture of solute dissolved in a solvent
Solubility - the quantity of solute that dissolves in a given quantity of solvent at a given temperature.
Precipitate- a solid produced from a chemical reaction.
Soluble:
If a substance is soluble, it can be dissolved in liquid. This means the particles are broken down to become so tiny we can no longer see them. Some examples of soluble materials are salt and sugar. The opposite of soluble is insoluble - a substance that cannot be dissolved.
Aqueous:
An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending to the relevant chemical formula.
Homogeneous:
A homogeneous mixture is a mixture of substances blended so thoroughly that you cannot see individual substances.
Chemical reactions in in industrial processes:
There are several chemical processes that create necessary materials in manufacturing. These include cement, steel, aluminum and fertilizer. The chemical process for cement is called calcination. For steel, the process is called smelting, which is done inside a blast furnace. The Hall Heroult process is used to make aluminum, while the Haboer process produces fertilizer.
Petrochemical Industry: The petrochemical industry deals with the production of chemicals and materials derived from petroleum and natural gas. Processes such as refining, cracking, and reforming involve high-temperature reactions and the use of hazardous substances. Accidental releases, leaks, or explosions in petrochemical plants can lead to severe health and safety hazards, including chemical exposure, fires, and toxic gas releases.
Industrial Combustion: Combustion processes used in power generation, industrial boilers, or waste incineration can have significant health and safety implications. Incomplete combustion or improper control of emissions can release pollutants such as particulate matter, sulfur dioxide, nitrogen oxides, or toxic gases into the air, contributing to air pollution and respiratory problems.
Mining and Metal Extraction: Various chemical reactions are involved in mining and metal extraction processes. For instance, the extraction of metals from ores often requires the use of chemical reagents, such as acids or cyanide, which can be hazardous if not managed properly. Additionally, the processing of minerals can generate dust, emissions, and waste products that may contain toxic substances.
Acid Base Neutralization:
An acid-base neutralization reaction is a type of chemical reaction that occurs when an acid reacts with a base, resulting in the formation of a salt and water. It is a specific type of double displacement reaction where the hydrogen ions (H+) from the acid combine with the hydroxide ions (OH-) from the base to form water (H2O). The remaining ions then combine to form a salt.
General Equation:
acid + base → salt + water
For example, let's consider the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH):
HCl + NaOH → NaCl + H2O
In this reaction, the hydrogen ions (H+) from hydrochloric acid combine with the hydroxide ions (OH-) from sodium hydroxide to form water (H2O). The remaining ions, sodium (Na+) from the base and chloride (Cl-) from the acid, combine to form sodium chloride (NaCl), which is a salt.
Combustion:
A combustion reaction is a type of chemicsl reaction that occurs between a fuel and an oxidizer, resulting in the release of heat and the formation of combustion products. t is a exothermic reaction, meaning it releases energy in the form of heat.
What is it?
In a combustion reaction, a hydrocarbon reacts with oxygen to form carbon dioxide and water. A complete combustion reaction produces only carbon dioxide and water (C6H12O6 + 6O2 -> 6CO2 + 6H2O). An incomplete combustion reaction produces carbon monoxide and water (C6H12O6 + 4O2 -> 6CO + 6H2O).
Equation:
Fuel + O2 → CO2 + H2O
In this equation, the hydrocarbon fuel combines with oxygen to produce carbon dioxide (CO2), water (H2O), and heat. The ratio of oxygen to fuel depends on the specific hydrocarbon and the stoichiometry of the reaction.
Incomplete combustion:
In incomplete combustion, there is not enough oxygen present for all of the hydrocarbons to be fully oxidized. As a result, some of the hydrocarbons react with oxygen to produce carbon monoxide (CO) instead of carbon dioxide. The equation for this reaction can be represented as CxHy + (x+y/4) O2 -> xCO2 + yH2O + xCO
Complete combustion:
In complete combustion, there is a sufficient amount of oxygen present for all of the hydrocarbons to be fully oxidized, resulting in the production of only carbon dioxide and water. The equation for this reaction can be represented as CxHy + (x+y/4) O2 -> xCO2 + (y/2) H2O
Subtopic
Synthesis Reaction:
A synthesis reaction, also known as a combination reaction, is a type of chemical reaction in which two or more substances combine to form a single, more complex product. In a synthesis reaction, the reactants react together to create a new compound.
What is it?
In a synthesis reaction, two or more reactants combine to form a single product. For example, the reaction between hydrogen and oxygen forms water (H2 + O2 -> 2H2O).
General Formula:
A + B --> AB
where A and B are the reactants, and AB is the product.
