Question

The molarity of $N{O}_3^{-}$ in the solution after $2L$ of $3MAgN{O}_3$ is mixed with $3L$ of $1MBaC{l}_2$ is

• A. 1.2 M
• B. 1.8 M
• C. 0.5 M
• D. 0.4 M

Answer 1

Answer: (A)

$2L$ of $3MAgN{O}_3$ will contains $6$ moles of $AgN{O}_3$.
$3L$ of $1MBaC{l}_2$ will contain $3$ moles of $BaC{l}_2$.
$2\mathrm{AgNO}{}_3+\mathrm{BaCl}{}_2\to 2\mathrm{AgCl}+\mathrm{Ba}(\mathrm{NO}{}_3){}_2\cdot$
So, 6 moles of $AgN{O}_3$ will react with 3 moles on $BaC{l}_2$ it means, two solution will react completely to form 3 moles of $Ba(N{O}_3{)}_2\equiv$ 6 moles of $N{O}_3^{-}$ ions in $2+35L$ solution
Hence, molarity of $N{O}_3^{-}=\frac{6}{5}=1.2M$