Question

How much $Ca{\left(N{O}_3\right)}_2$ in mg must be present in 50 g of a solution with 2.35 ppm of $Ca$?

• A. 0.1175
• B. 770.8
• C. 4.7
• D. 0.48

Answer 1

The correct option is D 0.48

$2.35$ $mg$ of $Ca$ is present in $1$ $kg$ of solution.

$⟹$ Mass of $Ca$ present in $50$ $gm$ solution $=2.35\times 0.05=0.1175$ $mg$

No. of moles $=\frac{0.1175}{40}$ $millimoles$

$1$ $mole$ $Ca(N{O}_3{)}_2$ has $1$ $mole$ of $C{a}^{+2}$ and $2$ $mole$ $N{O}_3^{2-}$ are present.

$⟹$ Moles of $Ca(N{O}_3{)}_2=\frac{0.1175}{40}$ $millimoles$

Mass of $Ca(N{O}_3{)}_2=\frac{0.1175}{40}\times 164=0.48$ $mg$