Question

The enthalpy of formation of C(coal,s) is -10kJ/mol, and the enthalpy of formation of carbon monoxide CO(g) is -110kJ/mol. When 10. moles of coal is burned to form carbon monoxide, 850 kJ of heat is released.

Calculate the percent yield of the reaction.

Answer 1

Theoretical reaction :

C+O -------------------> CO

Heat of reaction = enthalpy of formation of products - Enthalpy of formation of reactants = -110 kJ/mol.+10 kJ/mol

Heat of reaction = -100 kJ/mol.(heat released when 1 mol of coal was burnt )

Actual reaction:

For 10 mol of coal heat of reaction = -q (heat released)=-850 kJ

For 1 mol of coal burnt, -85 kJ/mol.

Yiled of the reaction = (actual heat released /theortical heat of reaction)*100 =-85 kJ/mol /-100 kJ/mol=85 %

Therefore, the yield of the reaction is 85 %