Question

Which Of the following 0.2m aqueous solutions will exhibit the largest freezing point depression. 1) glucose 2) sucrose 3)urea 4)nacl

Answer 1

The explanation for the correct option:

Option(4) NaCl

Freezing Point depression

• The freezing point depression is a colligative property.
• The colligative property depends upon the Vant Hoff factor​(i)
• Freezing point depression is given by the formula :

$\Delta T_f=i\times k_f\times m$

$where,\Delta T_f=freezingpointdepression$

$i=Va{n}^{\prime }thofffactor$

$k_f=cryoscopicconstant$

$m=molarity$

NaCl

• NaCl ​is an electrolyte, hence it dissociates into ions.​

$NaCl\left(aq\right)\Rightarrow {Na}^{+}+{Cl}^{-}(i=2)$

The explanation for the incorrect option:

(1) Glucose

• Glucose is a non-electrolyte, hence it does not dissociate into ions.​

$C_6{H}_{12}{O}_6\iff noions(i=0)$

(2) Sucrose

• Sucrose is a non-electrolyte, hence it does not dissociate into ions.​

$C_{12}{H}_{22}{O}_{11}\iff noions(i=0)$

(3) Urea

• Urea ​is a non-electrolyte, hence it does not dissociate into ions.​

$N{H}_{2}CON{H}_2\iff noions(i=0)$

Hence, Option(4) NaCl is correct Of the following 0.2m aqueous solution NaCl will exhibit the largest freezing point depression.