Thermochemistry
| Description: Thermochemistry Quiz | |
| Number of Questions: 15 | |
| Created by: Aliensbrain Bot | |
| Tags: thermochemistry chemical reactions energy transfer |
What is the term for the study of energy changes during chemical reactions?
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Thermochemistry
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Calorimetry
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Stoichiometry
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Kinetics
Thermochemistry is the branch of chemistry that deals with the energy changes that accompany chemical reactions.
What is the enthalpy change of a reaction?
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The change in internal energy of the system
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The change in entropy of the system
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The change in free energy of the system
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The change in volume of the system
The enthalpy change of a reaction is the change in the internal energy of the system, which includes the change in kinetic and potential energy of the molecules.
What is the difference between exothermic and endothermic reactions?
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Exothermic reactions release energy, while endothermic reactions absorb energy
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Exothermic reactions absorb energy, while endothermic reactions release energy
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Exothermic reactions have a positive enthalpy change, while endothermic reactions have a negative enthalpy change
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Exothermic reactions have a negative enthalpy change, while endothermic reactions have a positive enthalpy change
Exothermic reactions are those that release energy, while endothermic reactions are those that absorb energy.
What is the enthalpy of formation of a compound?
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The enthalpy change when the compound is formed from its elements
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The enthalpy change when the compound is decomposed into its elements
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The enthalpy change when the compound is burned in oxygen
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The enthalpy change when the compound is dissolved in water
The enthalpy of formation of a compound is the enthalpy change when the compound is formed from its elements.
What is the Hess's law of constant heat summation?
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The enthalpy change of a reaction is independent of the path taken
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The enthalpy change of a reaction is equal to the sum of the enthalpy changes of the individual steps of the reaction
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The enthalpy change of a reaction is equal to the difference between the enthalpy of the reactants and the enthalpy of the products
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The enthalpy change of a reaction is equal to the product of the enthalpy of the reactants and the enthalpy of the products
Hess's law of constant heat summation states that the enthalpy change of a reaction is equal to the sum of the enthalpy changes of the individual steps of the reaction.
What is the relationship between enthalpy and entropy?
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Enthalpy and entropy are always directly proportional
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Enthalpy and entropy are always inversely proportional
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Enthalpy and entropy are sometimes directly proportional and sometimes inversely proportional
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Enthalpy and entropy are unrelated
The relationship between enthalpy and entropy depends on the specific reaction. In some cases, enthalpy and entropy are directly proportional, while in other cases they are inversely proportional.
What is the Gibbs free energy of a reaction?
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The change in enthalpy of the reaction minus the product of the temperature and the change in entropy of the reaction
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The change in enthalpy of the reaction plus the product of the temperature and the change in entropy of the reaction
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The change in entropy of the reaction minus the product of the temperature and the change in enthalpy of the reaction
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The change in entropy of the reaction plus the product of the temperature and the change in enthalpy of the reaction
The Gibbs free energy of a reaction is the change in enthalpy of the reaction minus the product of the temperature and the change in entropy of the reaction.
What is the relationship between Gibbs free energy and spontaneity?
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A reaction is spontaneous if the Gibbs free energy of the reaction is positive
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A reaction is spontaneous if the Gibbs free energy of the reaction is negative
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A reaction is spontaneous if the Gibbs free energy of the reaction is zero
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A reaction is spontaneous if the Gibbs free energy of the reaction is equal to the enthalpy change of the reaction
A reaction is spontaneous if the Gibbs free energy of the reaction is negative.
What is the equilibrium constant of a reaction?
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The ratio of the concentrations of the reactants and products at equilibrium
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The ratio of the partial pressures of the reactants and products at equilibrium
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The ratio of the activities of the reactants and products at equilibrium
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The ratio of the standard free energies of the reactants and products
The equilibrium constant of a reaction is the ratio of the concentrations of the reactants and products at equilibrium.
What is the van't Hoff equation?
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An equation that relates the equilibrium constant of a reaction to the temperature
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An equation that relates the enthalpy change of a reaction to the temperature
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An equation that relates the entropy change of a reaction to the temperature
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An equation that relates the Gibbs free energy of a reaction to the temperature
The van't Hoff equation is an equation that relates the equilibrium constant of a reaction to the temperature.
What is the Arrhenius equation?
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An equation that relates the rate of a reaction to the temperature
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An equation that relates the rate of a reaction to the concentration of the reactants
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An equation that relates the rate of a reaction to the activation energy of the reaction
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An equation that relates the rate of a reaction to the equilibrium constant of the reaction
The Arrhenius equation is an equation that relates the rate of a reaction to the activation energy of the reaction.
What is the activation energy of a reaction?
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The minimum amount of energy that is required for a reaction to occur
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The maximum amount of energy that is released in a reaction
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The difference between the enthalpy of the reactants and the enthalpy of the products
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The difference between the Gibbs free energy of the reactants and the Gibbs free energy of the products
The activation energy of a reaction is the minimum amount of energy that is required for a reaction to occur.
What is a catalyst?
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A substance that increases the rate of a reaction without being consumed
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A substance that decreases the rate of a reaction without being consumed
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A substance that is consumed in a reaction and increases the rate of the reaction
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A substance that is consumed in a reaction and decreases the rate of the reaction
A catalyst is a substance that increases the rate of a reaction without being consumed.
What is the difference between a homogeneous and a heterogeneous catalyst?
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A homogeneous catalyst is in the same phase as the reactants, while a heterogeneous catalyst is in a different phase than the reactants
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A homogeneous catalyst is consumed in the reaction, while a heterogeneous catalyst is not consumed in the reaction
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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
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A homogeneous catalyst is more effective than 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.
What is the role of enzymes in biological reactions?
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Enzymes are catalysts that increase the rate of biological reactions
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Enzymes are catalysts that decrease the rate of biological reactions
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Enzymes are consumed in biological reactions and increase the rate of the reactions
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Enzymes are consumed in biological reactions and decrease the rate of the reactions
Enzymes are catalysts that increase the rate of biological reactions.