QJEEM20Ch2030: JEE Main 2020 Chemistry - Class 12 JEEM20Ch2030 Solution: How much amount of NaCl should be added to 600 g of water ( =…

Question

Verified Solution • 2025–26 Session moderate

How much amount of NaCl should be added to 600 g of water (

\rho

= 1.00 g/mL) to decrease the freezing point of water to – 0.2 °C ? ______.
(The freezing point depression constant for water = 2K kg mol^–1)

Accepted Answer

\Delta

T_f = 0.2^o C

\therefore

\Delta

T_f = ik_f.m

i = 2 for NaCl

\therefore

0.2 = 2

\times

2

\times

{{{W_{NaCl}} \times 1000} \over {58.5 \times 600}}

\Rightarrow

W_NaCl =

{{58.5 \times 600 \times 0.2} \over {4 \times 1000}}

= 1.76 g

Step-by-Step Verified Solution