Question

Five hundred milliliters of a solution of $0.1MNaBr$ has how many milligrams of bromine?

• A. $200mg$
• B. $400mg$
• C. $2,000mg$
• D. $4,000mg$

Answer 1

The correct option is D $4,000mg$

Molarity of NaBr $=\frac{\text{No. of moles of NaBr}}{\text{Volume (in L)}}$

$\Rightarrow 0.1=\frac{\text{No. of moles of NaBr}}{0.5}$

$\Rightarrow \text{No. of moles of NaBr}=0.05moles$

So, it contains $0.05moles$ of Bromine atoms.

$\Rightarrow$Mass of Bromine $=80\left(\text{Molecular mass of Bromine}\right)\times \left(0.05\right)=4g=4000mg$