Chapter 13, Problem 13.151QP

Nitrogen monoxide reacts with oxygen to give nitrogen dioxide.

$2\text{NO}(g)+{\text{O}}_2(g)\stackrel{}{\to }2{\text{NO}}_2(g)$

The rate law is −Δ[NO]/Δt = k[NO]²[O₂], where the rate constant is 1.16 × 10⁻³ L²/(mol² · s) at 339^oC. A vessel contains NO and O₂ at 339^oC. The initial partial pressures of NO and O₂ arc 155 mmHg and 345 mmHg, respectively. What is the rate of decrease of partial pressure of NO (in mmHg per second)? (Hint: From the ideal gas law, obtain an expression for the molar concentration of a particular gas in terms of its partial pressure.)