Question

6. The heat of a system at a constant pressure decreases by 401 J. What is the change in enthalpy?

A- 401 J
B- 200 J
C- -200 J
O- -401 J

Answer 1

When the heat of the system decreases, heat energy is dissipated to the surroundings. Hence, it is known as an exothermic reaction. All exothermic reactions have a enthalpy change of a negative value. Assuming all energy dissipated completely, the change in enthalpy is -401J