JEE Mains · Chemistry · STD 11 - 5. Thermodynamics and thermochemistry
A sample of n-octane \((1.14 \mathrm{~g})\) was completely burnt in excess of oxygen in a bomb calorimeter, whose heat capacity is \(5 \mathrm{~kJ} \mathrm{~K}^{-1}\). As a result of combustion reaction, the temperature of the calorimeter is increased by 5 K. The magnitude of the heat of combustion of octane at constant volume is ______ \(\mathrm{kJ} \mathrm{mol}^{-1}\) (nearest integer).
- A 3000
- B 2500
- C 200
- D 3500
Answer & Solution
Correct Answer
(B) 2500
Step-by-step Solution
Detailed explanation
\(\text { Mole of octane }=\frac{1.14}{114}=0.01 \mathrm{~mole}\) Heat evolved \(=\mathrm{C} \times \Delta \mathrm{T}\) \(\begin{aligned} & =5 \times 5 \mathrm{~kJ} \\ & =25 \mathrm{~kJ} \end{aligned}\) \(\therefore\) Magnitude of Heat of combustion \(=\frac{25}{0.01}=2500\)…
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