Question

Which of the following solutions is hypertonic?

• A. 0.1 M $FeC{l}_3$
• B. 0.1 M NaOH
• C. 0.1 M $N{a}_{2}S{O}_4$
• D. 0.1 M Urea

Answer 1

Answer: (A)

Osmotic Pressure$=i\times C\times R\times T$

where "i" is vant Hoffs factor

C is concentration , R is universal gas constant , T is absolute temperature

Hypertonic solution means pressure is highest in comparison to other solutions.

Since concentration, temperature and Universal gas constant are the same for all, hence the value of Osmotic Pressure would depend on vant Hoffs factor "i".

"i " means in how many total ions a compound would dissociate

i for $Fe{Cl}_3$ = 4 ( 1 Fe ion & 3 Cl ion)

i for $NaOH$ is 2 ( 1 Na ion & 1 OH ion )

i for Urea is 1

i for ${Na}_{2}S{O}_4$ is 3 ( 2 Na ion & 1 $S{O}_4$ ion )

Since "i" for $FeC{l}_3$= 4 is maximum in comparison to others, hence its pressure is maximum.

So $FeC{l}_3$ is hypertonic.