The heat of combustion of carbon to CO₂ is –393.5 kJ/mol. The heat released upon formation of 35.2 g of CO₂ from carbon and oxygen gas is (2015)

(None): Given: C(s) + O₂(g) → CO₂(g), ∆H = – 393.5 kJ/mol ⇒ Amount of heat released on formation of 44 g CO₂ = 393.5 kJ ∴ Amount of heat released on formation of 35.2 g of CO₂ = 393.5 44 × 35.2 = 314.8 ≈ 315 kJ Note: –ve or +ve sign considering the reaction is exothermic or endothermic.