Which of the following statements about the enthalpy of formation is true?

It is always negative.
It is the enthalpy change when one mole of a compound is formed from its elements.
It can be calculated using Hess's law only.
It is independent of the physical state of the reactants.

Which of the following statements about the enthalpy of formation is true?

Step 1: Understand what enthalpy means. Enthalpy is a measure of energy in a system.
Step 2: Know what formation means. Formation refers to creating something from its basic parts.
Step 3: Learn about standard states. Standard states are the most stable forms of elements at a specific temperature and pressure.
Step 4: Combine these ideas. The enthalpy of formation is the energy change when one mole of a compound is made from its elements in their standard states.
Step 5: Remember that this definition is important in chemistry for understanding how much energy is involved in making compounds.

No concepts available.