Chemistry Chapter 4: Reaction Rates and Equilibrium

A 3D structure representing the arrangement of atoms or ions in a crystal lattice.

A unit cell is the smallest repeating unit in a crystal lattice.

A cubic unit cell has equal edge lengths (a = b = c) and 90-degree angles between them.

A tetragonal unit cell has two equal edge lengths (a = b) and a different length for the third (c). All angles are 90 degrees.

An orthorhombic unit cell has three different edge lengths (a ≠ b ≠ c) and all angles are 90 degrees.

A hexagonal unit cell has two equal edge lengths (a = b), a different length for the third (c), and angles of 90 degrees and 120 degrees.

A rhombohedral (or trigonal) unit cell has three equal edge lengths (a = b = c), but all angles are equal and not necessarily 90 degrees.

A monoclinic unit cell has three different edge lengths (a ≠ b ≠ c). Two angles are 90 degrees, and the third is not.

A triclinic unit cell has three different edge lengths (a ≠ b ≠ c), and all three angles are different and not necessarily 90 degrees.

The force that holds atoms or ions together in a crystal lattice.

The force that holds molecules together in a crystal lattice.

Weak forces arising from temporary fluctuations in electron distribution around an atom or molecule.

Forces arising from the attraction between oppositely charged ions.

A type of chemical bond where atoms share electrons to achieve stability.

A type of chemical bond where electrons are free to move throughout the material, creating a strong attraction between atoms.

The number of moles of solute dissolved in 1 kg of solvent.

The number of moles of solute dissolved in 1 L of solution.

The number of gram equivalents of the solute dissolved in one litre of solution.

The mass of solute (in grams) dissolved in 100 mL of solution.

The mass of solute (in grams) dissolved in 100 g of solution.

The ratio of the number of moles of one component in a mixture to the total number of moles of all components in the mixture.

A way to express the concentration of a substance in a solution, particularly for dilute solutions. It is defined as the number of parts of solute per million parts of solution.

Used for expressing tiny amounts of a substance, commonly used for trace impurities in chemicals or contaminants in the environment

A solution where the components deviate from Raoult's Law and do not form an ideal mixture. The interactions between molecules of the same component are stronger than the interactions between molecules of different components.

A solution where the components obey Raoult's Law and form an ideal mixture. The interactions between molecules of the same component are similar to the interactions between molecules of different components.

A solution where the partial vapour pressure of each volatile component is directly proportional to its mole fraction in the solution. This means that the vapour pressure of a component in a solution is directly related to the amount of that component in the solution.

A type of solution where the vapour pressure of the mixture is less than the sum of the vapour pressures of the individual components. This indicates that the interactions between the molecules of the different components are stronger than the interactions between the molecules of the same component, leading to a decrease in the tendency of the molecules to escape into the vapour phase.

A type of solution where the vapour pressure of the mixture is greater than the sum of the vapour pressures of the individual components. This indicates that the interactions between the molecules of the different components are weaker than the interactions between the molecules of the same component, leading to an increase in the tendency of the molecules to escape into the vapour phase.

A mixture of two or more liquids that exhibits a constant boiling point. The composition of the vapour is the same as the composition of the liquid.

A type of azeotrope where the boiling point of the mixture is lower than the boiling points of the individual components.

A type of azeotrope where the boiling point of the mixture is higher than the boiling points of the individual components.

Properties of solutions that depend only on the number of solute particles, not their identity. Colligative properties include osmotic pressure, freezing point depression, boiling point elevation, and relative lowering of vapour pressure.

The pressure required to prevent the flow of solvent across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration.

The lowering of the freezing point of a solvent when a non-volatile solute is added.

The elevation of the boiling point of a solvent when a non-volatile solute is added.

The decrease in the vapour pressure of a solvent when a non-volatile solute is added.

The process by which molecules of a solvent move across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration.

The rate of a reaction is independent of the concentration of reactants. The reaction proceeds at a constant rate regardless of how much reactant is present.

The rate of a reaction is directly proportional to the concentration of one reactant. Doubling the concentration of that reactant doubles the rate of reaction.

The rate of a reaction is proportional to the product of the concentrations of two reactants, each raised to a power that may or may not be the same as its stoichiometric coefficient in the reaction equation.

A measure of how fast a reaction proceeds. It's expressed in units of mol L-1 s-1.

A reaction that appears to be of a higher order than it actually is due to the presence of a large excess of one reactant.

The time it takes for the concentration of a reactant to decrease to half its initial value.

The rate of a reaction is proportional to the square of the concentration of one reactant. The rate quadruples if the concentration doubles.

The time taken for the concentration of a reactant to decrease to half its initial value.

The half-life of a first-order reaction is independent of the initial concentration. It remains constant and is calculated using the equation t1/2 = 0.693/k.

The half-life of a second-order reaction is dependent on the initial concentration. It is halved when the initial concentration is doubled.

A graphical representation of the concentration of a reactant or product as a function of time. It provides information about the reaction rate and order.

A chemical reaction that can proceed in both directions, with reactants forming products and vice-versa. The reaction reaches equilibrium when the rates of the forward and reverse reactions are equal.

The state in a reversible reaction when the rates of the forward and reverse reactions are equal. The concentrations of reactants and products remain constant.