Ques. 1JEE Main 2024, 29 January (Evening Shift)
Standard enthalpy of vapourisation for CCl4 is 30.5 kJ mol-1. Heat required for vapourisation of 284 g of CCl4 at constant temperature is kJ. (Given molar mass in g mol-1; C = 12, Cl = 35.5)
Answer
56
Solution
Molar mass of CCl4 = 12 + 4(35.5) = 154 g mol-1
⇒ n = 284154 = 1.844 mol
∴ q = n × vapH = 1.844 × 30.5 = 56.2 kJ ≈ 56 kJ
Answer: 56