Can someone explain how to do this? Consider the following equation: 2ZnS(s) + 3O2(g) ---> 2ZnO(s) + 2SO2(g), ΔH° = –878.2 kJ. What is the enthalpy change when 223.9 g ZnS(s) reacts in excess oxygen?
In this question a chemical equation is given;
2ZnS + 3
as per the equation 2 moles of ZnS releases -872.8kJ of energy on reaction with Oxygen.
2 moles of ZnS = -872 kJ of heat energy
In terms of mass, 2 moles of ZnS has mass 2 x 97.5 g = 195 g
195 g of ZnS on reaction gives -878.2 kJ of heat energy.
1 g of ZnS releases = -878.2 kJ / 195 of heat energy
223.9 g of ZnS releases = -878.2 kJ x 223.9g / 195g
= -1008 kJ of heat energy.