An equilibrium mixture taken in 2 litre vessel of the reaction: $2 \mathrm{SO}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{SO}_3(\mathrm{~g})$ has 4 moles of $\mathrm{SO}_2, 3$ moles of $\mathrm{O}_2$ and 6 moles of $\mathrm{SO}_3$ then the value of equilibrium constant $\left(\mathrm{K}_c\right)$ will be:
$15 \mathrm{~mol} \mathrm{~L}^{-1}$
$0.75 \mathrm{~L} \mathrm{~mol}^{-1}$
$1.5 \mathrm{~L} \mathrm{~mol}^{-1}$
$0.15 \mathrm{~mol} \mathrm{~L}^{-1}$
A first order reaction is $50 \%$ complete in 30 minutes at 300 K and in 10 minutes at 320 K . The activation energy of the reaction ( $E_a$ ) is: $\left[R=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1} ; \log 2=0.3010 ; \log 3=0.4771\right]$
$75.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$43.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$23.7 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$52.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$
Which of the following factors is altered by the addition of a catalyst during a chemical reaction?
Internal energy
Activation energy
Enthalpy
Entropy
The standard enthalpies of formation of $\mathrm{CH}_4(\mathrm{~g}), \mathrm{CO}_2(\mathrm{~g})$ and $\mathrm{H}_2 \mathrm{O}(\mathrm{l})$ are $-74.8 \mathrm{~kJ} \mathrm{~mol}^{-1},-393.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $-285.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. Then the enthalpy change for the given reaction in $\mathrm{kJ} \mathrm{mol}^{-1}$ will be:
$$ 2 \mathrm{CH}_4(\mathrm{~g})+4 \mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{CO}_2(\mathrm{~g})+4 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) $$
$ -890.3$
$+890.3$
$+1780.6$
$ -1780.6$
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