Question

What mass of $\mathrm{Ca}$ will contain the same number of atoms as present in $3.2g$of $\mathrm{S}$.

Answer 1

Step 1:

According to the question,

if we have the same number of atoms of two elements i.e. sulfur and calcium then their number of moles should be equal to each other.

Step 2:

$So,molesofcalcium=molesofsulphur$

$$\begin{gathered} Giventhatmassofsulphur=3.2gm \\ Then,numberofmoles=\frac{Weight}{MolecularWeight} \end{gathered}$$

$$\begin{gathered} =\frac{3.2}{32} \\ =0.1mole. \end{gathered}$$

$$\begin{gathered} Assuming, \\ Massofcalcium=xg \\ Molarmassofcalcium=40g\left(given\right) \end{gathered}$$

$$\begin{gathered} \mathit{}\mathrm{Then},\mathrm{Moles}\mathrm{of}\mathrm{Ca}=\frac{x}{40} \\ 0.1=\frac{x}{40} \\ x=40\times 0.1 \\ x=4g \end{gathered}$$

Hence, We get that mass of calcium is $4g.$