Question

What is the standard heat of reaction for the formation of NO2(g) from NO(g) and O2(g)? Write the balanced equation first. You can find the standard heats of formation in table 17.4 of your book on page 580. (Show all work including the equation you use to solve). (5 points). See page 581 for an example.

Answer 1

The answer to your question is ΔHf = -114.2 kJ/mol

Step-by-step explanation:

Balanced chemical reaction

2NO(g) + O₂(g) ⇒ 2NO₂(g)

Standard heat of formation

ΔHf NO (g) = 90.3 kJ/mol

ΔHf O₂ (g) = 0.0 kJ/mol

ΔHf NO₂ (g) = 33.2 kJ/mol

- For this reaction

ΔHf = ∑ΔHf products - ∑Hf reactants

-Substitution

ΔHf = 2(33.2) - 2(90.3) - 0

-Simplification

ΔHf = 66.4 - 180.6

-Result

ΔHf = -114.2 kJ/mol