Which of the following equations corresponds to the definition of enthalpy of formation at 298 K?

Options

A. `C_((g)) + O_(2(g)) rarr CO_(2(g))`
B. `C_((s)) + O_(2(l)) rarr CO_(2(g))`
C. `C_((s)) + O_(2(g)) rarr CO_(2(g))`
D. `C_((l)) + O_(2(s)) rarr CO_(2(g))`

Answer

C

Explanation

Heat of formation is the quantity of heat exchanged when one mole of a substance is formed from its constituent elements under given condition of temperature and pressure. Under normal conditions, carbon is found in solid form and oxygen is found in gaseous form.