When of burns completely in excess at standard conditions

CHEMISTRY · Single correct · A Level · Chemistry · Energetics · Energetics

Problem

When

4.00\,\text{g}

\text{CH}_4(g)

burns completely in excess

\text{O}_2(g)

at standard conditions,

221\,\text{kJ}

of heat is released. The balanced chemical equation is

\text{CH}_4(g)+2\text{O}_2(g)\rightarrow\text{CO}_2(g)+2\text{H}_2\text{O}(l)

Given

\Delta H_f^\circ\bigl(\text{CH}_4(g)\bigr)=-75\,\text{kJ mol}^{-1}

and

\Delta H_f^\circ\bigl(\text{H}_2\text{O}(l)\bigr)=-286\,\text{kJ mol}^{-1}

, determine

\Delta H_f^\circ\bigl(\text{CO}_2(g)\bigr)

. (a)

-497\,\text{kJ mol}^{-1}

(b)

-387\,\text{kJ mol}^{-1}

(c)

-884\,\text{kJ mol}^{-1}

(d)

-718\,\text{kJ mol}^{-1}