The oxidation of copper(i) oxide, cu 2 o ( s ) , to copper(ii) oxide, cuo ( s ) , is an exothermic process. 2 cu 2 o ( s ) + o 2 ( g ) ⟶ 4 cuo ( s ) δ h ∘ rxn = − 292.0 kj mol calculate the energy released as heat when 54.08 g cu 2 o ( s ) undergo oxidation at constant pressure.

The value of for the reaction will be -55.48 kJ

Explanation:

To calculate the number of moles, we use the equation:

Given mass of copper (I) oxide = 54.08 g

Molar mass of copper (I) oxide = 143.1 g/mol

Putting values in above equation, we get:

For the given chemical reaction:

By Stoichiometry of the reaction:

When 2 moles of copper (I) oxide reacts, the energy evolved is 292.0 kJ

So, when 0.380 moles of copper (I) oxide will react, the energy evolved will be

Sign convention of heat:

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

Hence, the value of for the reaction will be -55.48 kJ

the answer is d. 74.02