Question

Calculate the mass of copper(II) sulphate formed when $2.5g$ of copper(II) oxides react with excess sulphuric acid. The equation for the given reaction is given below:
$CuO + {H_2}S{O_4} \to CuS{O_4} + {H_2}O$ (Atomic number of $Cu = 63,O = 16,S = 32$ )

Answer 1

Hint: The type of reaction between copper oxide and sulphuric acid is the type of double displacement reaction. In this type of reaction exchange of ions of compounds takes place. In order to calculate mass we will first find out the molecular masses.

Complete step by step answer:Given data:
The reaction is given as follows:
$CuO + {H_2}S{O_4} \to CuS{O_4} + {H_2}O$
In the reaction given above copper oxide reacts with concentrated sulphuric acid to give copper sulphate and water.
Molecular mass of copper sulphate $\left( {CuS{O_4}} \right) = $[atomic mass of $Cu + $ atomic mass of sulphur $\left( S \right) + 4 \times $ atomic mass of oxygen]
Substituting the values of mass of each element we get,
Molecular mass of copper sulphate $\left( {CuS{O_4}} \right) = 63 + 32 + 16\left( 4 \right)$
Molecular mass of copper sulphate $\left( {CuS{O_4}} \right) = 159g$
Molecular mass of copper oxide $\left( {CuO} \right) = $[atomic mass of $Cu + $atomic mass of oxygen]
Substituting the values of mass of each element we get,
Molecular mass of copper oxide $CuO = 63 + 16$
Molecular mass of copper oxide $CuO = 79g$
Mass of copper oxide $CuO$ when it reacts with excess sulphuric acid $ = 2.5g$
To find: mass of copper sulphate when $2.5g$ copper oxide reacts with sulphuric acid $ = ?$
Soln:
Mass of copper sulphate $\left( {CuS{O_4}} \right) = 159g$
Mass of copper oxide $\left( {CuO} \right) = 79g$
From the data given above we can say that,
$79g$ of copper oxide $CuO = 159g$ of copper sulphate $\left( {CuS{O_4}} \right)$
$2.5g$ of copper oxide $CuO = ?$ copper sulphate $\left( {CuS{O_4}} \right)$
Therefore,
Substituting the values of copper sulphate and copper oxide from the given data we get,
Amount of copper sulphate when $2.5g$ of copper oxide reacts with excess sulphuric acid $ = \dfrac{{2.5 \times 159}}{{79}}$
Amount of copper sulphate $ = \dfrac{{397.5}}{{79}}$
Amount of copper sulphate $ = 5.031g$
This means $5.031g$ of copper sulphate was formed when $2.5g$ of copper oxide reacts with excess sulphuric acid.

Note:
Molecular mass is the mass of a molecule which is measured in units of dalton represented by Da or u. Mathematically, the molecular mass of a given molecule is measured by the atomic mass of every element present in the molecular formula of the compound.