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

explanation:

specific heat is the amount of heat required to raise the temperature of a unit mass of a substance.

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.