Easy INTEGER +4 / -1 PYQ · JEE Mains 2021

83 g of ethylene glycol dissolved in 625 g of water. The freezing point of the solution is ____________ K. (Nearest integer)

[Use : Molal Freezing point depression constant of water = 1.86 K kg mol$-$1]

Freezing Point of water = 273 K

Atomic masses : C : 12.0 u, O : 16.0 u, H : 1.0 u]

Answer (integer) 269

Solution

k<sub>f</sub> = 1.86 kg/mol<br><br>T$_f^o$ = 273 K<br><br>solvent : H<sub>2</sub>O(625 g)<br><br>Solute : 83 g of ethylene glycol<br><br>$\Rightarrow$ $\Delta$T<sub>f</sub> = k<sub>f</sub> $\times$ m<br><br>$\Rightarrow$ $\left( {T_f^o - T_f^1} \right) = 1.86 \times {{83/62} \over {625/1000}}$<br><br>$$ \Rightarrow 273 - T_f^1 = {{1.86 \times 83 \times 1000} \over {62 \times 625}} = {{154380} \over {38750}}$$<br><br>$\Rightarrow 273 - T_f^1 = 4$<br><br>$\Rightarrow T_f^1 = 259$ K

About this question

Subject: Chemistry · Chapter: States of Matter · Topic: Gas Laws

This question is part of PrepWiser's free JEE Main question bank. 142 more solved questions on States of Matter are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →