A `Zn` rod weighing `1.0g` is taken in `100mL` of `1M CuSO_(4)` solution . After some time, `[Cu^(2+)]` in solution `=0.9M(` atomic weight of `Zn=65.5g)`. Which of the following statements is `//` are correct ?
`a. 0.655g` of `Zn` was lost during the reaction.
`b. 0.327 g `of `Zn` was lost during the reaction .
`c.` There is no change in the molarity of `SO_(4)^(2-)` ion.
`d.` There is a change in the molarity of `SO_(4)^(2-)` ion.

Answer

a,c

Explanation

`a. mEq.` of `Cu^(2+)` before reaction ltbr. `=100xx1xx2 ` `(n` factor for `Cu^(2+)=2)`
`=200`
`mEq` of `Cu^(2+)` after reaction `=100xx0.9xx2=180`
`mEq` of `Cu^(2+)` lost `=200-180=20`
`mEq` of `Zn` lost `=20`
Weight of `Zn` lost `=mEqxx10^(-3)xxEw` of `Zn`
`=90xx10^(-3)xx(65.5)/(2)`
`(n` factor for `Zn=2)`
`=0.655g`
`c.` There is no change in the molartiy of `SO_(4)^(2-)` ions, since `SO_(4)^(2-)` ions have not been oxidized and there is no change is the volume of solution .