Write a balanced chemical equation for the complete combustion of 1-butanol - HSC - SSCE Chemistry - Question 23 - 2010 - Paper 1

To determine which fuel is likely to be 1-butanol, we need to compare the heat of combustion values. The values for the fuels are:

• Fuel A: -48 kJ g⁻¹
• Fuel B: -38 kJ g⁻¹
• Fuel C: -28 kJ g⁻¹

The published heat of combustion for 1-butanol is significantly higher at 2676 kJ mol⁻¹. To convert this value to kJ g⁻¹, we first calculate the molar mass of 1-butanol:

$$Molar \, mass \, of \, C_4H_{10}O = 4(12) + 10(1) + 16 = 74 \, g/mol$$

Then, using the published value:

$$Heat \, of \, combustion \, = \frac{2676 \, kJ/mol}{74 \, g/mol} \approx 36.1 \, kJ/g$$

From the comparison:

• 36.1 kJ g⁻¹ is higher than all values listed for A, B, and C.

Thus, fuel B (-38 kJ g⁻¹) is the closest to the calculated value for 1-butanol, suggesting that it is likely to be 1-butanol.