Write the expression for the equilibrium constant Keq for the reaction below: 2CO(g) + O2(g) ⇔ 2CO2(g) a. [CO2] / [CO] [O2] b. [CO]2 / [CO2]2 [O2] c. [CO2]2 / [CO]2 [O2] d. [CO]2 [O2] / [CO2]2 Group of answer choices

The answer is NOT A. [CO2] / [CO] [O2]

just took the test and I chose A. The test did not tell me the correct answer. Sorry.

Explanation: NOT, I REPEAT NOT: A. [CO2] / [CO] [O2]

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.