The heat of combustion of butan-1-ol is 2676 kJ mol⁻¹ - HSC - SSCE Chemistry - Question 3 - 2005 - Paper 1

To convert the heat of combustion of butan-1-ol from kJ mol⁻¹ to kJ g⁻¹, we need to know the molar mass of butan-1-ol.

1. Determine the molecular formula of butan-1-ol, which is C₄H₉OH.

2. Calculate the molar mass:

   • Carbon (C): 4 × 12.01 g/mol = 48.04 g/mol
   • Hydrogen (H): 10 × 1.008 g/mol = 10.08 g/mol
   • Oxygen (O): 1 × 16.00 g/mol = 16.00 g/mol
   • Total molar mass = 48.04 + 10.08 + 16.00 = 74.12 g/mol

3. Now, convert the heat of combustion:

   • Heat of combustion = 2676 kJ/mol
   • Heat of combustion in kJ/g = (rac{2676 ext{ kJ/mol}}{74.12 ext{ g/mol}})

4. Perform the calculation:

   • (rac{2676}{74.12} \approx 36.10) kJ g⁻¹

Thus, the value of the heat of combustion in kJ g⁻¹ is approximately 36.10. Therefore, the correct answer is (B) 36.10.