Question

For the reaction CH₃OH_(aq) + Cl^-_(aq) <--> CH₃Cl_(aq) + OH^-_(aq) , K = 3.4 x 10^-15 at a particular temperature. What can be said about the relative energies of products and reactants?

Group of answer choices

products must be more stable

products and reactants must be of nearly equal stabilities

no way to determine without more information

reactants must be more stable

Answer 1

Ans- Reactants must be more stable

Explanation-

WE know for a chemical reaction, the equilibrium constant (K) at a partcular temperature is the ratio between the product of concentrations of products, each raised to the power of their number of moles involved to the product of concentrations of reactants, each raised to the power of their number of moles involved, present at tequilibrium.

i.e for the given reaction-   CH₃OH_(aq) + Cl^-_(aq) <--> CH₃Cl_(aq) + OH^-_(aq)

K = [OH^-] * [CH₃Cl] / [CH₃OH] * [Cl^-]

Now the given value of K = (3.4 x 10^-15)

That meeans K < 1

That means we have more reactants leaft than product. Or in other words we can say less amount of reactants are geting converted to products. It shows that reactants are more stable.

Again of we calculate the change in Gibbs free energy (ΔG) from the formula-

(ΔG) = -RT ln K

where

R = Gas constant = 0.008314 kJ/mole.K

T = Given kelvin temperature (positive number)

Then the ln K will have a negative value (as K <1)

So the overall vale of (ΔG) will be Positive. That means the reaction is Non- spontaneous.

So we can say the energy of Reactants are less than Prorducts. So reactants are more stable.