`10 g` of a sample of a mixture of `CaCl_(2)` and `NaCl` is treated to precipitate all the calcium as `CaCO_(3)`. This `CaCO_(3)` is heated to convert all the `Ca` to `CaO` and the final mass of `CaO` is 1.62 g.The percent by mass of `CaCl_(2)` in the origial mixture is

Options

A. `15.2%`
B. `32.1%`
C. `21.8%`
D. `11.07%`

Answer

B

Explanation

Moles of `CaO = (1.62)/(56) rArr " Moles of "CaCl_(2) = (1.62)/(56)`
`rArr` Mass of `CaCl_(2) = (1.62)/(5) xx 111 = 3.21 gm rArr % = (3.21)/(10) xx 100 = 32.1 %`