Question

Use standard enthalpies of formation to determine ΔHorxn for: 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(l)

Answer 1

Step-by-step explanation:

2C₂H₂(g) + 5O₂(g) → 4CO₂(g) + 2H₂O(l)

Enthalpies

C₂H₂(g) = 226.9 kJ/mol

O₂(g) = 0 kJ/mol

CO₂(g) = -393.5 kJ/mol

H₂O(l) = -285.5 kJ/mol

Formula

ΔH r = ∑npHp - ∑nrHp

Process

ΔHr = 4(-393.5) + 2(-285.5) - 2(226.9)

ΔHr = -1574 - 571 - 453.8

ΔHr = - 2598.8 kJ/mol

Answer 2

The answer to your question is: ΔHr = - 2598.8 kJ/mol

Step-by-step explanation:

2C₂H₂(g) + 5O₂(g) → 4CO₂(g) + 2H₂O(l)

Enthalpies

C₂H₂(g) = 226.9 kJ/mol

O₂(g) = 0 kJ/mol

CO₂(g) = -393.5 kJ/mol

H₂O(l) = -285.5 kJ/mol

Formula

ΔH r = ∑npHp - ∑nrHp

Process

ΔHr = 4(-393.5) + 2(-285.5) - 2(226.9)

ΔHr = -1574 - 571 - 453.8

ΔHr = - 2598.8 kJ/mol