In case of the reaction `A_(2)(g) +4B_(2)(g) hArr 2AB_(4)(g)`, the change in enthalpy `(DeltaH)` is negative. Mention the conditions of pressure and temperature at which the yield of the product, `AB_(4)(g)` will decrease.

Explanation

Since `DeltaH lt0`, it is an endothermic reaction. The volume of the reaction system decreases in the forward direction [1 molecule of `A_(2)(g)` combines with 4 molecules of `B_(2)(g)` to form 2 molecules of `AB_(4)(g)`]. Thus according to Le chatelier's principle, under the conditions of high temperature and low pressure, the yield of `AB_(4)(g)` will decrease.