Question

Hexane is a common laboratory solvent and a component of petrol. Its combustion reaction is as follows: 2 C6H14 (9) + 19 02(9) +12 CO2(g) + 14 H20(1) ArH=-8326 kJ mol-1 Use the reaction enthalpy value to calculate the heat in (kJ) released by combustion of 0.121 mol of hexane. (Give your answer as a positive number to at least THREE significant figures and do not include the units in the answer box)

Answer 1

Answer : The heat released by the combustion of 1.121 mol of hexane (kJ) is, $1.01\times 10^3$

Explanation :

The given balanced reaction is,

$2C_6H_{14}(g)+19O_2(g)\rightarrow 12CO_2(g)+14H_2O(l)$

Given:

Moles of hexane = 0.121 mol

$\Delta H$ = -8326 kJ/mol

The negative sign indicate that the reaction exothermic or amount of heat released.

As, 1 mole of hexane released heat = 8326 kJ

So, 0.121 mole of hexane released heat = 8326 × 0.121 = 1007.446 ≈ $1.01\times 10^3kJ$

Therefore, the heat released by the combustion of 1.121 mol of hexane is $1.01\times 10^3kJ$.