Question

Standard heat of formation for nitroglycerin...

A) +81 kJ/mol
B) +109 kJ/mol
C) +236 kJ/mol
D) +368 kJ/mol

Answer 1

The standard molar enthalpy of formation of NO(g) can be calculated using Hess's Law and the given data. The enthalpy change for the reaction N₂(g) + 2O₂(g) → 2NO₂(g) is 66.4 kJ. No options are applicable.

Step-by-step explanation:

The standard molar enthalpy of formation of NO(g) can be calculated using Hess's Law and the given data. We need to determine the enthalpy change for the reaction:

N₂(g) + 2O₂(g) → 2NO₂(g)

From the given data:

• AH°(N₂(g) + 2O₂(g) → 2NO₂(g)) = 66.4 kJ
• AH°(2NO(g) + O₂(g) → 2NO₂(g)) = -114.1 kJ

By adding these two reactions, we get:

2N₂(g) + 5O₂(g) → 4NO₂(g)

AH° = 66.4 kJ + (-114.1 kJ) = -47.7 kJ

Therefore, the standard molar enthalpy of formation of NO(g) is -47.7 kJ/mol.