Enthalpy Review Quiz

• The total pressure of the system

• The volume of the system

• The heat content of the system at constant pressure

• The total mass of the system

Which process is an example of an endothermic reaction?

• Combustion of propane

• Melting of ice

• Explosion of fireworks

• Burning of wood

Tags

NGSS.HS-PS1-4

What is a characteristic feature of an exothermic reaction?

• It requires heat to proceed

• It occurs spontaneously

• It releases heat to the surroundings

• It only occurs at high temperatures

What is the bond enthalpy of a chemical bond an indication of?

• The volume change during the reaction

• The pressure required to break the bond

• The color change when the bond breaks

• The energy required to break the bond in one mole of gaseous molecules

Tags

NGSS.HS-PS1-4

According to Hess's Law, how is the enthalpy change of a reaction determined?

• By the color change of the reactants and products

• By the sum of the enthalpy changes of individual steps in the reaction

• By the volume change of the system

• By the pressure change in the system

Tags

NGSS.HS-PS3-1

What does the enthalpy of combustion measure?

• The volume of gas produced when a substance burns

• The change in pressure when a substance burns

• The light emitted when one mole of a substance burns completely in oxygen

• The heat released when one mole of a substance burns completely in oxygen

For an exothermic reaction, how do the enthalpies of reactants and products compare?

• The enthalpy of the reactants is the same as the enthalpy of the products

• The enthalpy of the reactants is lower than the enthalpy of the products

• The enthalpy of the reactants is higher than the enthalpy of the products

• The enthalpy of the reactants and products cannot be determined

Tags

NGSS.HS-PS1-4

If the total bond enthalpy of the reactants is 800 kJ/mol and that of the products is 600 kJ/mol, what is the enthalpy change of the reaction?

• 200 kJ/mol absorbed

• 1400 kJ/mol released

• 200 kJ/mol released

• 1400 kJ/mol absorbed

Tags

NGSS.HS-PS1-4

How can Hess's Law be utilized to find the enthalpy change for a reaction that is difficult to measure directly?

• By measuring the change in volume of the reactants and products

• By adding the enthalpy changes of individual steps that lead from reactants to products

• By observing the color change during the reaction

• By calculating the change in pressure during the reaction

• The reaction is at equilibrium

• The reaction is endothermic

• The reaction is exothermic

• The reaction does not proceed