Question

Give the ΔH value for the decomposition of silver chloride as shown in the reaction 2AgCl(s)+127 kJ→2Ag(s)+Cl2(g).

Answer 1

Answer: $\Delta H=+127kJ$

Explanation:

$2AgCl(s)+127kJ\rightarrow 2Ag(s)+Cl_2(g)$  

Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and $\Delta H$ for the reaction comes out to be negative.

Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and $\Delta H$ for the reaction comes out to be positive.

As the heat is absorbed the reactants , the reaction is endothermic and $\Delta H$ for the given endothermic reaction will be +127 KJ