Question

A sample of hexane (C6H14) has a mass of 0. 580 g. The sample is burned in a bomb calorimeter that has a mass of 1. 900 kg and a specific heat of 3. 21 J/giK. What amount of heat is produced during the combustion of hexane if the temperature of the calorimeter increases by 4. 542 K? Use q equals m C subscript p Delta T. 8. 46 kJ 16. 1 kJ 27. 7 kJ 47. 8 kJ.

Answer 1

Explanation:We first calculate the heat released:

Specific heat = 3.21 kJ/kgK

Heat released = heat absorbed by calorimeter

Heat absorbed = mcΔT

= 1.9 x 3.21 x 4.542

= 27.7 kJ

Now, we calculate the moles of hexane present:

Moles = mass / Mr

moles = 0.58 / (12 x 6 + 14)

= 0.0067

Heat of combustion = 27.7 / 0.0067 kJ/mol

ΔH(combustion) = 4,134.3 kJ / mol