If the standard molar enthalpy change for combustion of graphite powder is $-2.48 \times 10^{2} \mathrm{~kJ} \mathrm{~mol}^{-1}$, the amount of heat generated on combustion of 1 g of graphite powder is _____ kJ. (Nearest integer)

JEE Main · 2021 · 22 Jul 2021 · Shift 2 · Chemical Thermodynamics

If the standard molar enthalpy change for combustion of graphite powder is

- 2.48 \times 1 0^{2} kJ mol^{- 1}

, the amount of heat generated on combustion of 1 g of graphite powder is _____ kJ. (Nearest integer)

Answer: 21

Solution

The standard enthalpy of combustion is quoted for one mole of graphite, and one mole of carbon weighs 12 g. The magnitude of the heat released on burning 1 g is therefore

q = \frac{2.48 \times 1 0 ^{2}}{12} = 20.67 kJ

To the nearest integer the heat generated on combustion of 1 g of graphite is

21

kJ.

JEE Main · 2021 · 22 Jul 2021 · Shift 2 · Integer answer

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