How much copper can be obtained from 100 g of copper sulphate (CuSO4)?

The correct option is 39.81g.

To determine the mass of copper ($\mathrm{Cu}$) that can be obtained from 100 g of copper sulphate (${\mathrm{CuSO}}_4$), we first need to calculate the molar mass of copper sulphate.

The atomic masses of the constituent elements are:
Copper ($\mathrm{Cu}$) = 63.55 g/mol
Sulfur ($S$) = 32.06 g/mol
Oxygen ($O$) = 16.00 g/mol

The molar mass of copper sulphate (${\mathrm{CuSO}}_4$) is calculated as:
Molar mass of ${\mathrm{CuSO}}_4$ = (Atomic mass of $\mathrm{Cu}$) + (Atomic mass of $S$) + 4 × (Atomic mass of $O$)

$\text{Molar mass of}{\mathrm{CuSO}}_4=63.55+32.06+(4\times 16.00)=63.55+32.06+64.00=159.61\text{g/mol}$

This means that 159.61 g of ${\mathrm{CuSO}}_4$ contains 63.55 g of copper.

Now, we can find the mass of copper in 100 g of ${\mathrm{CuSO}}_4$ using a simple ratio:

$\text{Mass of copper}=\frac{\text{Atomic mass of}\mathrm{Cu}}{\text{Molar mass of}{\mathrm{CuSO}}_4}\times \text{Given mass of}{\mathrm{CuSO}}_4$

$\text{Mass of copper}=\frac{63.55}{159.61}\times 100\text{g}$

$\text{Mass of copper}\approx 0.39816\times 100\text{g}\approx 39.81\text{g}$

Therefore, approximately 39.81 g of copper can be obtained from 100 g of copper sulphate.