Question

Calculate the AHrxn from the AH of formation for the following reaction. C2H4(g) + 302(g) 2C02(g) + 2H20(1). Formation AH values for C2H4(g) = 52.30 kJ/mol, for 02(g) = 0 kJ/mol, for CO2(g) = -393.5 kJ/mol and for H20(1) =-285.8kJ/mol.A. -1305kJB. 1350kJC. 1411kJD. -1411kJ

Answer 1

Answer

A. -1305 kJ

Explanation

Given:

Equation: C2H4(g) + 302(g) ---- > 2C02(g) + 2H20(l).

Formation ΔH values:

​​for C2H4(g) = 52.30 kJ/mol,

for 02(g) = 0 kJ/mol,

for CO2(g) = -393.5 kJ/mol, and

for H20(1) = -285.8kJ/mol.

What to find:

The ΔHrxn from the ΔH of formation for the given reaction.

Step-by-step solution:

ΔHrxn = (Sum of ΔH formation for the product) - (Sum of ΔH formation for the reactants).

ΔHrxn = (ΔH for 2CO2(g) + ΔH for 2H2O(l)) + (ΔH for C2H4(g) + ΔH for 3O2(g))

ΔHrxn = [(2 x -393.5) + (2 x -285.8)] + [52.30 + (3 x 0)]

ΔHrxn =(-787.0 - 571.6) + (52.30 + 0)

ΔHrxn = -1358.6 + 52.30

ΔHrxn = -1306.3 kJ

so the closest answer is A. -1305 kJ