Question

Describe a reversible reaction using the sample equation below. Include forward reaction and reverse reaction in your discussion.

2SO2 (g) + O2(g) <--> 2SO3 (g)

Answer 1

The equilibrium constant is defined as the ratio between the product of the equilibrium concentrations of the products and the product of the equilibrium concentrations of the reactants, all raised to the power of their respective stoichiometric coefficients in the chemical equation.

For the given equation,

2SO2(g] + O2(g] ⇌ 2SO3(g]

This reaction has two reactants, SO2 and O2, and one product, SO3. This tells that the equilibrium constant will feature three terms.

The equilibrium constant for the forward reaction will be,

Kc =
`([SO3]^(2))/([SO2]^2. [O2])`

We can write equilibrium constant for the reverse reaction K′c, using the same approach,

2SO2(g] + O2(g] ⇌ 2SO3(g]

The reaction has one product and two reactants, so the equilibrium constant for the reverse reaction will be,

K'c =
`([SO2]^2. [O2])/([SO3]^(2))`

Remember,

K'c = 1 / Kc