Question

The ionic stregth of `Na^(+)` on mixing `100 mL 0.1 NaCl` and `100 mL 0.1 N Na_(2)SO_(4)` is:
A. (a)`0.2`
B. (b)`0.1`
C. (c )`0.3`
D. (d)`0.075`

Answer 1

Correct Answer - d
`M_(1)V_(1)+M_(2)V_(2)=M_(3)V_(3)`
`0.1xx100+2xx0.1xx100=x+200`
Conc. Of `Na^(+)=(100xx0.1)/200+(100xx0.1xx2)/200=0.15 M`
:. Ionic strength`=1/2 CZ^(2)=1/2xx[0.15xx1^(2)]=0.075`