JEE Advanced 2012 Paper 2 Chemistry Q7

Chemistry · The First Law & Thermochemistry

Problem

Using the data provided, calculate the multiple bond energy (

\mathrm{kJ\,mol^{-1}}

) of a

\mathrm{C\equiv C}

bond in

\mathrm{C_2H_2}

. That energy is (take the bond energy of a

\mathrm{C-H}

bond as

350\,\mathrm{kJ\,mol^{-1}}

\begin{aligned}2\mathrm{C(s)}+\mathrm{H_2(g)}&\longrightarrow\mathrm{C_2H_2(g)}&\Delta H&=225\,\mathrm{kJ\,mol^{-1}}\\2\mathrm{C(s)}&\longrightarrow2\mathrm{C(g)}&\Delta H&=1410\,\mathrm{kJ\,mol^{-1}}\\\mathrm{H_2(g)}&\longrightarrow2\mathrm{H(g)}&\Delta H&=330\,\mathrm{kJ\,mol^{-1}}\end{aligned}