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2021 11 questions

Q882021 · 26 Aug 2021 · Shift 2· Numerical answer
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 $= 273 K$ $Atomic masses : C : 12.0 u$ , $O : 16.0 u$ , $H : 1.0 u$ ]
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Answer: 269
Q872021 · 27 Jul 2021 · Shift 2· Numerical answer
In a solvent 50% of an acid HA dimerizes and the rest dissociates. The van't Hoff factor of the acid is __________ $\times 1 0^{- 2}$ . (Round off to the nearest integer)
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Answer: 125
Q882021 · 25 Jul 2021 · Shift 2· Numerical answer
When 3.00 g of a substance 'X' is dissolved in 100 g of $CC l_{4}$ , it raises the boiling point by 0.60 K. The molar mass of the substance 'X' is ____ $g mo l^{- 1}$ . (Nearest integer). [Given $K_{b}$ for $CC l_{4}$ is 5.0 K kg $mo l^{- 1}$ ]
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Answer: 250
Q622021 · 22 Jul 2021 · Shift 2
Which purification technique is used for high boiling organic liquid compound (decomposes near its boiling point)?
1. A.Simple distillation
2. B.Steam distillation
3. C.Fractional distillation
4. D.Reduced pressure distillation
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Answer: D
Q732021 · 22 Jul 2021 · Shift 2
Which one of the following 0.06 M aqueous solutions has lowest freezing point?
1. A. $A l_{2} (S O_{4})_{3}$
2. B. $C_{6} H_{12} O_{6}$
3. C.KI
4. D. $K_{2} S O_{4}$
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Answer: A
Q882021 · 18 Mar 2021 · Shift 1· Numerical answer
2 molal solution of a weak acid HA has a freezing point of $- 3.88 5^{\circ} C$ . The degree of dissociation of this acid is ____ $\times 1 0^{- 3}$ . (Round off to the Nearest Integer). [Given : Molal depression constant of water = $1.85 K kg mo l^{- 1}$ , Freezing point of pure water = $0^{\circ} C$ ]
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Answer: 50
Q892021 · 18 Mar 2021 · Shift 2· Numerical answer
A solute A dimerizes in water. The boiling point of a 2 molal solution of A is $100.5 2^{\circ} C$ . The percentage association of A is ____. (Round off to the Nearest Integer). [Use : $K_{b}$ for water $= 0.52 K kg mo l^{- 1}$ Boiling point of water $= 10 0^{\circ} C$ ]
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Answer: 100
Q872021 · 16 Mar 2021 · Shift 1· Numerical answer
$A B_{2}$ is $10%$ dissociated in water to $A^{2 +}$ and $B^{-}$ . The boiling point of a 10.0 molal aqueous solution of $A B_{2}$ is _______ $^{\circ} C$ . (Round off to the Nearest Integer). [Given : Molal elevation constant of water $K_{b} = 0.5 K kg mol^{- 1}$ , boiling point of pure water $= 10 0^{\circ} C$ ]
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Answer: 106
Q862021 · 26 Feb 2021 · Shift 1· Numerical answer
$224 mL$ of $S O_{2 (g)}$ at $298 K$ and $1 atm$ is passed through $100 mL$ of $0.1 M NaOH$ solution. The non-volatile solute produced is dissolved in $36 g$ of water. The lowering of vapour pressure of solution (assuming the solution is dilute) $(P_{(H_{2} O)}^{o} = 24 mm of Hg)$ is $x \times 1 0^{- 2} mm of Hg$ , the value of x is _________. (Integer answer)
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Answer: 18 to 24
Q812021 · 26 Feb 2021 · Shift 2· Numerical answer
When 12.2 g of benzoic acid is dissolved in 100 g of water, the freezing point of solution was found to be $- 0.9 3^{\circ} C$ ( $K_{f} (H_{2} O) = 1.86 K kg mo l^{- 1}$ ). The number (n) of benzoic acid molecules associated (assuming 100% association) is _________.
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Answer: 2
Q832021 · 25 Feb 2021 · Shift 2· Numerical answer
If a compound AB dissociates to the extent of 75% in an aqueous solution, the molality of the solution which shows a 2.5 K rise in the boiling point of the solution is ____ molal. (Rounded off to the nearest integer) $[K_{b} = 0.52 K kg mo l^{- 1}]$
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Answer: 3