An equilibrium mixture of CO,O₂ and CO₂ at a certain temperature contains 0.0010 M CO₂ and 0.0020 M O₂.At this temperature,K_c equals 1.4 × 10² for the reaction: 2 CO(g) + O₂(g) ⇌ 2 CO₂(g) .
What is the equilibrium concentration of CO?

Question

Quizplus · Accepted Answer

Let the equilibrium concentration of CO be x. Then, using the given equilibrium concentrations and stoichiometry of the reaction:

Kc = ( [COS]^2 ) / ( [CO]^2 [OCS] )
1.4*10^-12 = ( 0.0010 M )^2 / ( x^2 * 0.0020 M )

Solving for x gives:

x = 1.9*10^-3 M

Therefore, the equilibrium concentration of CO is 1.9*10^-3 M or 1.9*10^-3 mol/L or 1.9 mM.

The correct answer choice is B.

An Equilibrium Mixture of CO,O2 and CO2 at a Certain

An Equilibrium Mixture of CO,O₂ and CO₂ at a Certain