# Can someone explain how to do this? Consider the following equation: "2ZnS" + "3O"_2 rarr "2ZnO" + "2SO"_2 , ΔH° = - 878.2kJ. What is the enthalpy change when 0.96 g ZnO is produced?

Oct 11, 2014

When 0.96g of zinc oxide is produced, the enthalpy change is

-5.15 kJ.

2 moles ZnS produce 2 moles ZnO to give 878.2 kJ of energy which is released to the surroundings:

Convert moles to grams:

[ Ar (Zn) = 65.28 Ar (S) = 32.06 Ar (O) = 16]

2 x (65.28 + 32.06) g ZnS$\rightarrow$2x (65.28 + 16 ) ZnO to give out 878.2 kJ

So

194.68g ZnS$\rightarrow$ 162.56g ZnO to give out 878.2 kJ of energy.

So 162.56 g of ZnO produces 878.2 kJ of energy

So 1g of ZnO produces 872.8/162.56 = 5.37 kJ of energy

So 0.96 g of ZnO will produce 5.37 x .96= 5.15 kJ of energy