Question

Calcium carbide can be made by heating calcium oxide with carbon. How many kj of heat are absorbed in the reaction?

Answer 1

Answer:

179Kj/mol

Explanation:

The equation for the reaction is:

CaO + 3C     ⇒   CaC₂ + CO ₂

The formula for calculating the heat absorbed is:

      ∆Hf (Products) - ∆Hf (Reactants)

Using the heat of formation (∆Hf) for each component in the reaction

∆Hf Cao = -635kj/mol

∆Hf C = 0kj/mol

∆Hf CaC2 = -63kj/mol

∆Hf CO2 = -393.5

The heat absorbed = ( -63 + -393.5) – (-635)

                                  = -  456 + 635

                                  = 179kj/mol