Question

Find the number of moles in $7\mathrm{g}$ of $\mathrm{Na}$

• A. $1\mathrm{mole}$
• B. $0.304\mathrm{mole}$
• C. $0.5\mathrm{mole}$
• D. $0.25\mathrm{mole}$

Answer 1

The correct option is B

$0.304\mathrm{mole}$

The correct option is option B

Step 1: Given data

Given the mass of sodium$=7\mathrm{g}$

Step 2: Calculating moles of sodium

Given the mass of sodium$=7\mathrm{g}$

The molar mass of sodium$=23\mathrm{g}$

Moles$=\frac{\mathrm{Given}\mathrm{mass}}{\mathrm{Molar}\mathrm{mass}}$

$=\frac{7\mathrm{g}}{23\mathrm{g}}\Rightarrow 0.304\mathrm{mole}$

Therefore, The number of moles in $7\mathrm{g}$ of $\mathrm{Na}$ is $0.304\mathrm{mole}$.