`100 ml` of `0.1 N` hypo decolourised iodine by the addition of x g of crystalline copper sulphate to excess of KI. The value of 'x' is (molecular wt. of `CuSO_(4).5H_(2)O is 250)`

Options

A. (a)` 5.0 g`
B. (b)` 1.25 g`
C. (c )` 2.5 g`
D. (d)`4 g `

Answer

C

Explanation

`overset(+2)(Cu)SO_(4)+2Kl rarr K_(2)SO_(4)+overset(+2)(CuI_(2)), 2overset(CuI_(2)) rarr overset(+1)(CuI_(2))+I_(2)`
`I_(2)+Na_(2)S_(2)O_(3) rarr 2NaI+Na_(2)S_(4)O_(6)`
Eq. wt. Of `CuSO_(4). 5H_(2)O-Mol. Wt =250`
`100 ml` of `0.1 N hypo-= 100ml` of `0.1 N CuSO_(4).5H_(2)O`
`=(250xx0.1xx100)/100=2.5 g`