Question

Enthalpy of combustion of carbon to CO2 is -393.5 kJ mol2. Calculate the
heat released on formation of 26.4g of CO2 , by combustion of carbon.

Answer 1

We have,

C

6

H

6

(l)+

2

15

O

2

(g)−>6CO

2

+3H

2

O

Therefore, ∆n = 6 – 15/2 = – 3/2

Also, ∆U per mol =–(327×78)/7.8

= –3270kJ

Therefore, ∆H = ∆U+∆nRT

=–3270+(–3/2)×300×10

–3

Or, ∆H = –3273.735 (B