Question

Calcium chloride, when dissolved in water, dissociates into its ions according to the following equation :

$CaC{l}_2\left(aq\right)\to C{a}^{2+}\left(aq\right)+2C{l}^{-}\left(aq\right)$

The number of ions obtained from $CaC{l}_2$ when 222 g of it is dissolved in water are :

• A. $1.2044\times {10}^{24}ions$
• B. $1.8066\times {10}^{24}ions$
• C. $2.4044\times {10}^{24}ions$
• D. $3.6132\times {10}^{24}ions$

Answer 1

Answer: (D)

$3.6132\times {10}^{24}ions$

$1mole\to 111g$ of $CaC{l}_2$

$\therefore 222g$ of $CaC{l}_2$ is equivalent to 2 moles of $CaC{l}_2$

Since 1 formula unit $CaC{l}_2$ gives 3 ions, therefore, 1 mol of $CaC{l}_2$

will give 3moles of ions

2 moles of $CaC{l}_2$ would give $3\times 2=6$ moles of ions.

No. of ions $=$ No. of moles of ions X Avogadro number

$=6\times 6.022\times {10}^{23}$

$=36.132\times {10}^{23}$

$=3.6132\times {10}^{24}ions$

Hence the correct option is D.