Question

The concentration of chloride ion, in molarity, in a solution containing $10.56$ g $BaC{l}_2.8H_{2}O$ per litre of solution is $(Ba=137)$:

• A. $0.06$ M
• B. $0.07$ M
• C. $0.18$ M
• D. $0.21$ M

Answer 1

The correct option is A $0.06$ M

The molar mass of $BaC{l}_2.8H_{2}O$ is $352.23$ g/mol.

$10.56$ g of $BaC{l}_2.8H_{2}O$ corresponds to $\frac{10.56}{352.23}=0.03$ moles. It is present in $1$ L of solution.

Hence, the molarity of $BaC{l}_2.8H_{2}O$ is $0.03$ M.

$1$ mole of $BaC{l}_2.8H_{2}O$ gives two moles of chloride ions. Hence, the molarity of chloride ions is $2\times 0.03=0.06M$.