Quiz: Enthalpy

ΔH value in an endothermic reaction is a positive number.

• True
• False

Define standard enthalpy of formation.

• Heat released when one mole of substance is burnt completely in excess oxygen.

• Heat absorbed when one mole of substance is burnt completely in excess oxygen under standard state.

• Heat released when one mole of substance is burnt completely in excess oxygen under standard state.

• Heat change when one mole of substance is burnt partially in excess oxygen under standard state.

Describe the energy change that takes place when bonds are broken. 

• a) Energy is given out 
• b) Energy is taken in 
• c) Energy is taken in and then given out 
• d) Energy is given out and then taken in

Which is an example of an endothermic physical reaction? 

• a) Ice melting 
• b) Combustion 
• c) Steam condensing 
• d) Photosynthesis

Exothermic Reaction

• reaction that gives heat to the surroundings

• reaction that takes heat from the surroundings

• reaction at constant pressure

• reaction at a constat speed

Enthalpy of Reaction

• change in Enthalpy during a reaction
• part of the Universe that is being studied
• reaction at constant pressure
• speed of a reaction

ΔH_rxn

• symbol for enthalpy of reaction

• symbol for enthalpy

• exothermic reaction

• difference in altitude

• exothermic reaction

• endothermic reaction

• reaction with catalyst

• equilibrium reaction

• endothermic reaction

• exothermic reaction

• reaction with catalyst

• equilibrium reaction

ΔH_rxn =

• H_products - H_reactants

• H_reactants - H_products

• H_products + H_reactants

• H_reactants / H_products