Use the data from table to estimate the enthalpy of formation of $\mathrm{CH}_3 \mathrm{CHO}$.

Use the data from table to estimate the enthalpy of formation of $\mathrm{CH}_3 \mathrm{CHO}$.
  1. $-200 \mathrm{~kJ} \mathrm{~mol}^{-1}$
  2. $-400 \mathrm{~kJ} \mathrm{~mol}^{-1}$
  3. $-350 \mathrm{~kJ} \mathrm{~mol}^{-1}$
  4. $-150 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Solution

$2 \mathrm{C}+2 \mathrm{H}_2+\frac{1}{2} \mathrm{O}_2 \longrightarrow \mathrm{CH}_3 \mathrm{CHO}$ $\Delta H_f=\Sigma \mathrm{BE}_{\text {(reactants) }}-\Sigma \mathrm{BE}_{\text {(products) }}$
$=2450-2650$ $=-200 \mathrm{~kJ} / \mathrm{mol}$

Asked in: AP EAMCET 2022 (05 Jul Shift 1)

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