JEE PYQ: Solutions And Colligative Properties Question 11
Question 11 - 2021 (26 Feb Shift 1)
224 mL of $\text{SO}2(g)$ at 298 K and 1 atm is passed through 100 mL of 0.1M NaOH solution. The non-volatile solute produced is dissolved in 36 g of water. The lowering of vapour pressure of solution ($P^0{\text{H}_2\text{O}} = 24$ mm of Hg) is $a \times 10^{-1}$ mm of Hg, the value of $a$ is ____.
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Answer: 6
Solution
NaOH is limiting reagent. 0.01 mol NaOH $\rightarrow$ 0.005 mol $\text{Na}_2\text{SO}_3$. $\text{Na}_2\text{SO}_3 \rightarrow 2\text{Na}^+ + \text{SO}_3^{2-}$, $i = 3$. Lowering in pressure $= 0.18$ mm of Hg $= 18 \times 10^{-1}$ mm of Hg.
BETA
