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प्रश्न
If the combustion of 1g of graphite produces 20.7 kJ of heat, what will be molar enthalpy change? Give the significance of sign also.
उत्तर
Molar enthalpy change for graphite (ΔH)
= enthalpy change for 1 g × molar mass of C = – 20.7 × 12 = – 2.48 × 102 kJ mol–1
Since the sign of ΔH = – ve, it is an exothermic reaction.
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