Question

`0.7 g "of" Na_(2)CO_(3).xH_(2)O` were dissolved in water and the volume was made to `100 mL, 20 mL` of this solution required `19.8 mL "of" N//10 HCl` for complete neutralization. The value of `x` is:
A. `7`
B. `3`
C. `2`
D. `5`

Answer 1

Correct Answer - C
Meq. of `Na_(2)CO_(3).xH_(2)O "in" 20 mL=19.8xx(1)/(10)`
`:.` Meq.of `Na_(2)CO_(3).xH_(2)O "in" 100 mL=19.8xx(1)/(10)xx5`
`:. (w)/(E )xx1000=19.8xx(1)/(10)xx5`
or `(0.7)/(M//2)xx1000=(19.8)/(2)`
`:. M= 141.41`
`23xx2+12+3xx16+18x=141.41`
`:. x=2`