Which statement is FALSE?

a. ΔErxn is a measure of heat.

b. Enthalpy is the sum of a system's internal energy and the product of pressure and volume.

c. ΔHrxn is the heat of reaction.

d. An exothermic reaction gives heat off heat to the surroundings.

e. Endothermic has a positive ΔH.

The false statement is a. ΔErxn is a measure of heat.

Explanation:

ΔErxn represents the energy change in a chemical reaction. However, in real processes the energy change is not only a measure of heat but also other forms like work and potential and kinetic energy.

Enthalpy is actually defined like the sum of a system's internal energy and the product of pressure and volume, so b is correct.

ΔHrxn is also the heat of reaction, which is also true

The last ones are also true