Question

For enthalpy reference state is at which the enthalpy is

(a) Zero

(b) Positive

(c) Negative

(d) None of the mentioned

This question was addressed to me in an internship interview.

The origin of the question is Energy Balances for a Chemical Reaction in section Energy Balances of Chemical Process Calculation

Answer 1

The correct answer is:

(a) Zero

The enthalpy reference state is typically chosen such that the enthalpy is zero at a particular reference point, often at a standard temperature and pressure (STP). This allows for easier calculation and comparison of changes in enthalpy.