Question

The complete combustion of ethanol, C2H5OH(l), to form H2O(g) and
CO2. Write a balanced thermochemical equation for this
reaction.

Answer 1

Answer:

C

2

H

5

OH(l)+3O

2

(g)⟶2CO

2

(g)+3H

2

O(l)

enthalpy of combustion, Δ

C

H

Δ

C

H=ΔU

C

+(Δn)

g

RT

Where ΔU

C

→ heat produced.

(Δn)

g

→ change in number of moles of gaseous molecules.

T=25

o

C=273+25=298K

∴Δ

C

H=−1364.47KJ+(−1)×8.314×10

−3

×298K

=−(1364.47 kJ+2.48 kJ)

=−1366.95 kJ/mol

∴ Enthalpy of combustion for ethanol.

Δ

C

H=−1366.95KJ/mol