Question

urgent

5) For a particular chemical reaction it is found that the value for the equilibrium constant for the reaction decreases as temperature increases. Based on this we can conclude a) AS rx < 0 b) ASX>0 c) AHºrxn < 0 d) AHºx>0 e) AGºrxn <0

Answer 1

Equilibrium constant (Kc) = product of concentration of products to the product of concentration of reactants while each concentration term has a raise to power equal to their stoichiometric coefficient.

As Kc is decreasing with increasing temperature , we can say that concentration of products is decreasing with increasing temperature.

This indicates that reaction equilibrium shifts backward on increasing the temperature and this is the characteristic of an exothermic reaction.

For an exothermic reaction , equilibrium shifts backward on raising the temperature.

dH°rxn for an exothermic reaction is always negative.

So we can conclude that dH°rxn < 0 .

Option (c) is the correct answer.