Questions
Question 1 Multiple Choice (Single Answer)
What is the term for the study of energy changes during chemical reactions?
- Thermochemistry
- Calorimetry
- Stoichiometry
- Kinetics
Question 2 Multiple Choice (Single Answer)
What is the enthalpy change of a reaction?
- The change in internal energy of the system
- The change in entropy of the system
- The change in free energy of the system
- The change in volume of the system
Question 3 Multiple Choice (Single Answer)
What is the difference between exothermic and endothermic reactions?
- Exothermic reactions release energy, while endothermic reactions absorb energy
- Exothermic reactions absorb energy, while endothermic reactions release energy
- Exothermic reactions have a positive enthalpy change, while endothermic reactions have a negative enthalpy change
- Exothermic reactions have a negative enthalpy change, while endothermic reactions have a positive enthalpy change
Question 4 Multiple Choice (Single Answer)
What is the enthalpy of formation of a compound?
- The enthalpy change when the compound is formed from its elements
- The enthalpy change when the compound is decomposed into its elements
- The enthalpy change when the compound is burned in oxygen
- The enthalpy change when the compound is dissolved in water
Question 5 Multiple Choice (Single Answer)
What is the Hess's law of constant heat summation?
- The enthalpy change of a reaction is independent of the path taken
- The enthalpy change of a reaction is equal to the sum of the enthalpy changes of the individual steps of the reaction
- The enthalpy change of a reaction is equal to the difference between the enthalpy of the reactants and the enthalpy of the products
- The enthalpy change of a reaction is equal to the product of the enthalpy of the reactants and the enthalpy of the products
Question 6 Multiple Choice (Single Answer)
What is the relationship between enthalpy and entropy?
- Enthalpy and entropy are always directly proportional
- Enthalpy and entropy are always inversely proportional
- Enthalpy and entropy are sometimes directly proportional and sometimes inversely proportional
- Enthalpy and entropy are unrelated
Question 7 Multiple Choice (Single Answer)
What is the Gibbs free energy of a reaction?
- The change in enthalpy of the reaction minus the product of the temperature and the change in entropy of the reaction
- The change in enthalpy of the reaction plus the product of the temperature and the change in entropy of the reaction
- The change in entropy of the reaction minus the product of the temperature and the change in enthalpy of the reaction
- The change in entropy of the reaction plus the product of the temperature and the change in enthalpy of the reaction
Question 8 Multiple Choice (Single Answer)
What is the relationship between Gibbs free energy and spontaneity?
- A reaction is spontaneous if the Gibbs free energy of the reaction is positive
- A reaction is spontaneous if the Gibbs free energy of the reaction is negative
- A reaction is spontaneous if the Gibbs free energy of the reaction is zero
- A reaction is spontaneous if the Gibbs free energy of the reaction is equal to the enthalpy change of the reaction
Question 9 Multiple Choice (Single Answer)
What is the equilibrium constant of a reaction?
- The ratio of the concentrations of the reactants and products at equilibrium
- The ratio of the partial pressures of the reactants and products at equilibrium
- The ratio of the activities of the reactants and products at equilibrium
- The ratio of the standard free energies of the reactants and products
Question 10 Multiple Choice (Single Answer)
What is the van't Hoff equation?
- An equation that relates the equilibrium constant of a reaction to the temperature
- An equation that relates the enthalpy change of a reaction to the temperature
- An equation that relates the entropy change of a reaction to the temperature
- An equation that relates the Gibbs free energy of a reaction to the temperature
Question 11 Multiple Choice (Single Answer)
What is the Arrhenius equation?
- An equation that relates the rate of a reaction to the temperature
- An equation that relates the rate of a reaction to the concentration of the reactants
- An equation that relates the rate of a reaction to the activation energy of the reaction
- An equation that relates the rate of a reaction to the equilibrium constant of the reaction
Question 12 Multiple Choice (Single Answer)
What is the activation energy of a reaction?
- The minimum amount of energy that is required for a reaction to occur
- The maximum amount of energy that is released in a reaction
- The difference between the enthalpy of the reactants and the enthalpy of the products
- The difference between the Gibbs free energy of the reactants and the Gibbs free energy of the products
Question 13 Multiple Choice (Single Answer)
What is a catalyst?
- A substance that increases the rate of a reaction without being consumed
- A substance that decreases the rate of a reaction without being consumed
- A substance that is consumed in a reaction and increases the rate of the reaction
- A substance that is consumed in a reaction and decreases the rate of the reaction
Question 14 Multiple Choice (Single Answer)
What is the difference between a homogeneous and a heterogeneous catalyst?
- A homogeneous catalyst is in the same phase as the reactants, while a heterogeneous catalyst is in a different phase than the reactants
- A homogeneous catalyst is consumed in the reaction, while a heterogeneous catalyst is not consumed in the reaction
- A homogeneous catalyst increases the rate of the reaction by increasing the concentration of the reactants, while a heterogeneous catalyst increases the rate of the reaction by decreasing the activation energy of the reaction
- A homogeneous catalyst is more effective than a heterogeneous catalyst
Question 15 Multiple Choice (Single Answer)
What is the role of enzymes in biological reactions?
- Enzymes are catalysts that increase the rate of biological reactions
- Enzymes are catalysts that decrease the rate of biological reactions
- Enzymes are consumed in biological reactions and increase the rate of the reactions
- Enzymes are consumed in biological reactions and decrease the rate of the reactions