The reaction occurs at standard conditions with an enthalpy change of

CHEMISTRY · Single correct · CBSE · Chemistry · Thermodynamics · Thermodynamics

Problem

The reaction

2\text{NO}(g)+\text{O}_2(g)\rightarrow 2\text{NO}_2(g)

occurs at standard conditions with an enthalpy change of

\Delta H^\circ_{\text{rxn}}=-114\,\text{kJ}

. Given

\Delta H_f^\circ\bigl(\text{NO}_2(g)\bigr)=-33\,\text{kJ mol}^{-1}

, what is the standard enthalpy of formation,

\Delta H_f^\circ

, of

\text{NO}(g)

? (a)

-24\,\text{kJ mol}^{-1}

(b)

+48\,\text{kJ mol}^{-1}

(c)

+24\,\text{kJ mol}^{-1}

(d)

-90\,\text{kJ mol}^{-1}