Chemistry Equilibrium and Reaction Rates Quiz

A measure of the disorder or randomness in a system. It is a thermodynamic property that reflects the number of possible arrangements of the particles in a system.

The standard entropy of a substance represents the entropy change when it is heated from 0 K to 298 K at a constant pressure of 100 kPa. It's essentially the entropy value at standard conditions.

The change in entropy during a chemical reaction can be calculated by subtracting the sum of the entropies of the reactants from the sum of the entropies of the products.

A process with a positive entropy change (∆S > 0) is favored by entropy. This means the system tends to become more disordered.

A process with a negative entropy change (∆S < 0) is disfavored by entropy. This means the system tends to become more ordered.

Energy cannot be created or destroyed, only transferred or transformed.

In an isolated system not at equilibrium, entropy will always increase over time. This means the system will become more disordered as it approaches equilibrium.

The entropy of a system approaches a minimum value as the temperature approaches absolute zero (0 Kelvin). At absolute zero, the system has minimal disorder.

The pressure that a gas in a mixture would exert if it were the only gas present in that volume.

The sum of the partial pressures of all the gases in a mixture.

When the pressure of a system is increased, the system will shift towards the side with fewer moles of gas to counteract the change, reducing the pressure.

The partial pressure of a gas increases when the number of moles of that gas per unit volume increases, according to the ideal gas law (P α n/V).

In a reaction involving gases, Le Chatelier's Principle applies to the partial pressure of individual gases, not the total pressure.

A reaction where carbon dioxide and water react with light energy to form glucose and ATP. It occurs in plants.

A chemical reaction with a positive enthalpy change (∆𝐻 > 0), meaning it requires energy to proceed.

A measure of disorder or randomness in a system. It tends to increase in spontaneous reactions.

A measure of the total energy change in a reaction, including both enthalpy and entropy. It determines if a reaction is spontaneous or not.

A reaction with a negative Gibbs Free Energy change (∆𝐺 < 0), meaning it releases energy and is spontaneous.

A reaction with a positive Gibbs Free Energy change (∆𝐺 > 0), meaning it requires energy input to proceed.

A reaction that can proceed in both the forward and reverse directions, depending on the conditions.

The process of breaking down glucose to produce energy, occurring in living organisms.

A change to the system results in a shift towards the opposite direction, but it will never completely counteract the change or overcompensate.

A substance that speeds up a reaction without being consumed. It provides an alternate pathway with lower activation energy.

The rate of the forward and reverse reactions increase.

Dinitrogen tetroxide: Colorless. Nitrogen dioxide: Brown or reddish-brown.

The equilibrium constant (Keq) will change with temperature, and the position of the equilibrium will shift accordingly.

The process of dissolving a solid in a liquid where the solute-solute interactions, solvent-solvent interactions, and ion-dipole forces are overcome, resulting in the solutes dispersing throughout the solvent.

An individual molecule or ion surrounded by solvent molecules, forming a sphere of solvation.

The process of breaking apart the ionic lattice of a solid, requiring energy input. The process of forming new ion-dipole attractions between these ions and solvent molecules releases energy.

The enthalpy change associated with dissolving one mole of a substance in a solvent.

The entropy of a system increases during dissolution as the free movement of ions in solution is greater than their constrained movement in a crystal lattice.

An equilibrium state where the rate of dissolution equals the rate of crystallization, resulting in a constant concentration of dissolved solute.

A solution that contains less solute than its solubility limit at a given temperature.

A solution that contains the maximum amount of dissolved solute at a given temperature.

Catalysts increase the rates of both the forward and reverse reactions equally, meaning they do not shift the equilibrium position. The equilibrium constant remains unchanged.

The forward reaction is endothermic; it requires heat. When the reaction mixture is heated, the equilibrium shifts to the right, favoring the forward reaction. This results in more product formation. Cooling the solution favors the reverse, exothermic reaction, resulting in more reactants.

The forward reaction of the equilibrium [Co(H2O)6]^2+ + 4Cl^- ⇌ [CoCl4]^2- + 6H2O absorbs heat, making it endothermic.

Nitrogen dioxide (NO2) is a brown gas, while dinitrogen tetroxide (N2O4) is colorless.