Question

copper metal can be produced by heating copper(1) oxide and hydrogen gas. another product of the reaction is water. if the molar enthalpy of reaction (δrh) is +130.5 kj/mol, calculate the enthalpy of reaction for producing 2.0 g of copper metal.

Explanation:

Step1: Determine the molar mass of copper

The molar mass of copper ($Cu$) is $M = 63.5\ g/mol$.

Step2: Calculate the number of moles of copper

The mass of copper is $m = 2.0\ g$. The number of moles $n=\frac{m}{M}=\frac{2.0\ g}{63.5\ g/mol}$.

Step3: Calculate the enthalpy change

The molar - enthalpy of the reaction is $\Delta H = + 130.5\ kJ/mol$. The enthalpy change $\Delta H_{rxn}=n\times\Delta H=\frac{2.0\ g}{63.5\ g/mol}\times130.5\ kJ/mol$.

Answer:

$4.1\ kJ$