Question

Calculate the following:
The mass of 0.25 moles of Calcium.

Answer 1

• The atomic mass of Calcium ($\mathrm{Ca}$) is 40 g.
• Let X be the unknown mass (in grams) of 0.25 moles of Calcium.
• $$\begin{gathered} 1\text{mole of Ca}=\text{Gram atomic mass of Ca}=40g \\ \mathrm{No}.\mathrm{of}\mathrm{moles}\mathrm{of}\mathrm{Ca}=\frac{\mathrm{Given}\mathrm{mass}\mathrm{of}\mathrm{Ca}}{\mathrm{Atomic}\mathrm{mass}\mathrm{of}\mathrm{Ca}} \\ \Rightarrow 0.25=\frac{\mathrm{X}}{40} \\ \Rightarrow \mathrm{X}=10\mathrm{g} \end{gathered}$$
• Hence, the mass of 0.25 moles of Calcium is 10 g.