1.2 % NaCl solution is isotonic with 7.2 % glucose solution. What will be the van't Hoff factor, i?

Options

A. `0.5`
B. `1`
C. `2`
D. `6`

Answer

C

Explanation

For `NaCl pV = nST xx i`
`p_i xx 100/1000 = 1.2/58.5 xx 0.821 xx T xx i " " ...(i)`
For glucose, `pV = nST`
`p_2 xx 100/100 = 7.2/180 xx 0.0821 xx T " "…(ii) `
`because NaCl` and glucose solutions are isotonic
`therefore p_1 = p_2`
On dividing Eq. (i) by (ii), we have
`i = 7.2/180 xx 58.5/1.2 = 1.95= 2`