Choose the reaction, for which the standard enthalpy of reaction is equal to the standard enthalpy of formation:

Options

A. `2H_(2)(g) + O_(2)(g) rarr 2H_(2)O (l)`
B. `2C(g) +3H_(2) (g) rarr C_(2)H_(6)(g)`
C. `1/8 S_(8)(s) + O_(2)(g) rarr SO_(2)(g)`
D. `3/2 O_(2)(g) rarr O_(3)(g)`

Answer

C, D

Explanation

Standard formation of enthalpy is the enthalpy involved in the reaction when one mole of a substance is formed from its constituent elements in their standard elemental state.
`{:(1/8 S(8)(s) + O_(2)(g), rarr SO_(2)(g)),(3/2 O_(2)(g),rarr O_(3)(g)):}}` from action reactions .