Question

If $12$ drops of $AgN{O}_3$ solution are used to reach the colour point, what mass of chloride ion is present in one litre sample?

• A. $6.52$ g
• B. $0.150$ g
• C. $0.125$ g
• D. $1.25$ g

Answer 1

Answer: (A)

$6.52$ g

One drop $AgN{O}_3=12.5\times {10}^{-3}$ g ${Cl}^{-}$
$\therefore$ $12$ drops $AgN{O}_3=12.5\times {10}^{-3}\times 12$ g ${Cl}^{-}$ $=150\times {10}^{-3}$ g ${Cl}^{-}$
So, $23$ mL sample $=0.15$ g ${Cl}^{-}$
$1000$ mL sample $=\frac{0.15\times 1000}{23}$ g/L ${Cl}^{-}=6.52$ g.