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?

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Answer 1 · 2014-10-11T23:59:27

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#rarr#2x (65.28 + 16 ) ZnO to give out 878.2 kJ

So

194.68g ZnS#rarr# 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