Chem 110 Exam 2 Practice Questions & Answer Key

These flashcards include important terms, definitions, and concepts from the Chem 110 exam material, focused on chemical quantities, gases, solutions, and acids and bases.

Molar Mass

The mass of one mole of a substance, typically expressed in grams per mole (g/mol).

Balanced Equation

An equation in which the number of atoms for each element is the same on both sides.

Oxidation

The process in which a substance loses electrons; typically increases oxidation state.

Reduction

The process in which a substance gains electrons; typically decreases oxidation state.

Exothermic Reaction

A reaction that releases energy in the form of heat.

Endothermic Reaction

A reaction that absorbs energy from its surroundings.

Boyle's Law

States that the pressure of a gas is inversely proportional to its volume at constant temperature.

Charles's Law

States that the volume of a gas is directly proportional to its temperature at constant pressure.

Dalton's Law of Partial Pressures

The total pressure of a gas mixture is the sum of the partial pressures of the individual gases.

Hydrogen Bonding

A strong type of dipole-dipole attraction between molecules, involving a hydrogen atom bonded to a highly electronegative atom.

Mass Percent

A calculation that gives the concentration of a component in a mixture, expressed as the mass of the component divided by the total mass of the solution, multiplied by 100.

Saturated Solution

A solution in which no more solute can dissolve at a given temperature and pressure.

Buffer Solution

A solution that resists changes in pH upon the addition of small amounts of acid or base.

Conjugate Acid-Base Pair

A pair of compounds that differ by the presence or absence of a proton (H+).

pH Scale

A logarithmic scale used to specify the acidity or basicity of an aqueous solution.

Strong Electrolyte

A substance that completely dissociates into ions in solution.

Weak Electrolyte

A substance that partially dissociates into ions in solution.

Neutralization Reaction

A chemical reaction between an acid and a base that produces salt and water.

Hydronium Ion ([H3O+])

A water molecule that has an extra proton, acting as a measure of acidity in solution.

Molarity (M)

A concentration unit defined as the number of moles of solute divided by the liters of solution.

Aqueous Solution

A solution in which water is the solvent.

Volume-Temperature Relationship

As the temperature of a gas increases, its volume also increases at constant pressure.

Ideal Gas Law

The equation of state for an ideal gas, expressed as PV=nRT.

Kinetic Molecular Theory

A theory that explains the gas laws in terms of the motion of the molecules.

Density of Gases

Mass per unit volume of a gas, often described in g/L.

Stoichiometry

The calculation of reactants and products in chemical reactions.

Limiting Reactant

The reactant that is fully consumed first in a reaction, limiting the amount of product formed.

Excess Reactant

The reactant that remains after a chemical reaction has gone to completion.

Electrolysis

A process that uses electricity to drive a chemical reaction.

Catalyst

A substance that increases the rate of a chemical reaction without being consumed.

Colloid

A mixture where tiny particles are dispersed in a continuous medium.

Solution

A homogeneous mixture formed when a solute is dissolved in a solvent.

Solvent

The substance in which the solute is dissolved to form a solution.

Solute

The substance that is dissolved in a solution.

Dissociation

The process by which a compound breaks apart into its component ions.

Equilibrium

A state in which the concentrations of reactants and products remain constant over time.

Ionization

The process by which an atom or molecule gains or loses electrons, forming ions.

Solubility Product Constant (Ksp)

A constant equilibrium expression for the solubility of a sparingly soluble ionic compound.

Le Chatelier's Principle

If an external change is applied to a system at equilibrium, the system adjusts to counteract that change.

Hydrate

A compound that contains water molecules in its crystalline structure.

Gas Laws

Equations that describe the behavior of gases under varying conditions of temperature, pressure, and volume.

Molar Volume of an Ideal Gas

The volume occupied by one mole of a gas at standard temperature and pressure (STP), approximately 22.4 L.

Henry’s Law

States that the amount of gas dissolved in a liquid is proportional to the partial pressure of the gas.

Arrhenius Acid

A substance that increases the concentration of H3O+ ions in aqueous solution.

Arrhenius Base

A substance that increases the concentration of OH- ions in aqueous solution.

Molar Mass

The mass of one mole of a substance, typically expressed in grams per mole (g/mol). Formula: $M = \frac{m}{n}$, where (M) is molar mass, (m) is mass (g), and (n) is amount of substance (mol).

Balanced Equation

An equation in which the number of atoms for each element is the same on both sides. Example: $2H<em>2 + O</em>2 \rightarrow 2H_2O$.

Oxidation

The process in which a substance loses electrons; typically increases oxidation state. Example: $Fe \rightarrow Fe^{2+} + 2e^-$.

Reduction

The process in which a substance gains electrons; typically decreases oxidation state. Example: $Cu^{2+} + 2e^- \rightarrow Cu$.

Exothermic Reaction

A reaction that releases energy in the form of heat. Example: $C + O<em>2 \rightarrow CO</em>2 + \text{energy}$.

Endothermic Reaction

A reaction that absorbs energy from its surroundings. Example: $NH<em>4Cl + \text{heat} \rightarrow NH</em>4^+ + Cl^-$.

Boyle's Law

States that the pressure of a gas is inversely proportional to its volume at constant temperature. Formula: $P<em>1V</em>1 = P<em>2V</em>2$.

Charles's Law

States that the volume of a gas is directly proportional to its temperature at constant pressure. Formula: $\frac{V<em>1}{T</em>1} = \frac{V<em>2}{T</em>2}$.

Dalton's Law of Partial Pressures

The total pressure of a gas mixture is the sum of the partial pressures of the individual gases. Formula: $P<em>{total} = P</em>1 + P<em>2 + P</em>3 + …$.

Hydrogen Bonding

A strong type of dipole-dipole attraction between molecules, involving a hydrogen atom bonded to a highly electronegative atom.

Mass Percent

A calculation that gives the concentration of a component in a mixture. Formula: $\% \text{mass} = \left(\frac{m<em>{component}}{m</em>{solution}}\right) \times 100$.

Saturated Solution

A solution in which no more solute can dissolve at a given temperature and pressure.

Buffer Solution

A solution that resists changes in pH upon the addition of small amounts of acid or base.

Conjugate Acid-Base Pair

A pair of compounds that differ by the presence or absence of a proton (H+).

pH Scale

A logarithmic scale used to specify the acidity or basicity of an aqueous solution. Formula: $pH = -\log[H_3O^+]$.

Strong Electrolyte

A substance that completely dissociates into ions in solution.

Weak Electrolyte

A substance that partially dissociates into ions in solution.

Neutralization Reaction

A chemical reaction between an acid and a base that produces salt and water. Example: $HA + BOH \rightarrow BA + H_2O$.

Hydronium Ion ([H3O+])

A water molecule that has an extra proton, acting as a measure of acidity in solution.

Molarity (M)

A concentration unit defined as the number of moles of solute divided by the liters of solution. Formula: $M = \frac{n}{V}$.

Aqueous Solution

A solution in which water is the solvent.

Volume-Temperature Relationship

As the temperature of a gas increases, its volume also increases at constant pressure.

Ideal Gas Law

The equation of state for an ideal gas, expressed as $PV=nRT$.

Kinetic Molecular Theory

A theory that explains the gas laws in terms of the motion of the molecules.

Density of Gases

Mass per unit volume of a gas, often described in g/L. Formula: $\text{Density} = \frac{m}{V}$.

Stoichiometry

The calculation of reactants and products in chemical reactions.

Limiting Reactant

The reactant that is fully consumed first in a reaction, limiting the amount of product formed.

Excess Reactant

The reactant that remains after a chemical reaction has gone to completion.

Electrolysis

A process that uses electricity to drive a chemical reaction.

Catalyst

A substance that increases the rate of a chemical reaction without being consumed.

Colloid

A mixture where tiny particles are dispersed in a continuous medium.

Solution

A homogeneous mixture formed when a solute is dissolved in a solvent.

Solvent

The substance in which the solute is dissolved to form a solution.

Solute

The substance that is dissolved in a solution.

Dissociation

The process by which a compound breaks apart into its component ions.

Equilibrium

A state in which the concentrations of reactants and products remain constant over time.

Ionization

The process by which an atom or molecule gains or loses electrons, forming ions.

Solubility Product Constant (Ksp)

A constant equilibrium expression for the solubility of a sparingly soluble ionic compound.

Le Chatelier's Principle

If an external change is applied to a system at equilibrium, the system adjusts to counteract that change.

Hydrate

A compound that contains water molecules in its crystalline structure.

Gas Laws

Equations that describe the behavior of gases under varying conditions of temperature, pressure, and volume.

Molar Volume of an Ideal Gas

The volume occupied by one mole of a gas at standard temperature and pressure (STP), approximately 22.4 L.

Henry’s Law

States that the amount of gas dissolved in a liquid is proportional to the partial pressure of the gas.

Arrhenius Acid

A substance that increases the concentration of H3O+ ions in aqueous solution.

Arrhenius Base

A substance that