For the allotropic change represented by the equation: C(graphite) -> C(diamond); δ H = +1.9 kJ. If — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

The reaction C(graphite) -> C(diamond) is endothermic by 1.9 kJ/mol. This means diamond is at a higher energy state than graphite by 1.9 kJ/mol, so its combustion will release 1.9 kJ/mol more heat than graphite. For 6.0 g of Carbon (which is 0.5 mole): Extra heat liberated by diamond = 0.5 mol * 1.9 kJ/mol = 0.95 kJ. Thus, heat liberated is higher by 0.95 kJ in case of diamond.