The values of van’t Hoff factors for KCl, NaCl and K₂SO₄ respectively are:

Three aqueous solutions of NaCl are labelled as ‘A', ‘B’ and ‘C with concentrations 0.1 M, 0.01 M and 0.001 M, respectively. The value of van’t Hoff factor for these solutions will be in the order of :

1. i_A < i_B < i_C

2. i_A > i_B > i_C

3. i_A = i_B = i_C

4. i_A < i_B > i_C

The van't hoff factor (i) is given by the expression:

(a) $i=\frac{\text{\hspace{0.17em}Normal molar mass\hspace{0.17em}\hspace{0.17em}}}{\text{abnormal molar mass}}$

(b) $i=\frac{\text{\hspace{0.17em}Abnormal molar mass\hspace{0.17em}\hspace{0.17em}}}{\text{normal molar mass}}$

(c) $i=\frac{\text{\hspace{0.17em}Observed colligative property\hspace{0.17em}\hspace{0.17em}}}{\text{calculated colligative property}}$

(d) $i=\frac{\text{\hspace{0.17em}Calculated colligative property\hspace{0.17em}\hspace{0.17em}}}{\text{observed colligative property}}$

The correct choice among the given options is:

1. a and b

2. b and c

3. c and d

4. a and c