Question

Calculate the heat of combustion of ethylene (gas) to form CO2(gas) and H2O (gas) at 298Kand 1 atmospheric pressure. The heats of formation of CO2, H2O and C2H4are –394, -242,+52kJ per mole respectively.C2H4(g) + 3O2(g)--2CO2(g) + 2H2O (g)​

Answer 1

Answer:

Solution:-

Combustion of C

2

H

4

-

C

2

H

4

(g)

+3O

2

(g)

⟶2CO

2

(g)

+2H

2

O

(l)

For the above reaction-

ΔH=∑ΔH

f

P

−∑ΔH

f

R

ΔH=(2×(−394)+2×(−286))−(52+0)

ΔH=−1360+52=−1308kJ/mol

Hence the enthapy of combustion of C

2

H

4

(g)

is −1308kJ/mol