CBSE 2023 · Region 1 · Set 2 · Q26 · 3 marks
Give reason:(a)Measurement of osmotic pressure method is preferred for the determination of molar masses of macromolecules such as proteins and polymers.(b)Aquatic animals are more comfortable in cold water than in warm water.(c)Elevation of boiling point of $\displaystyle 1$ M KCl solution is nearly double than that of $\displaystyle 1$ M sugar solution.
Give reason:
(a)
Measurement of osmotic pressure method is preferred for the determination of molar masses of macromolecules such as proteins and polymers.
(b)
Aquatic animals are more comfortable in cold water than in warm water.
(c)
Elevation of boiling point of $\displaystyle 1$ M KCl solution is nearly double than that of $\displaystyle 1$ M sugar solution.
Marking-scheme solution
(a) Osmotic pressure is measured at room temperature / molarity of the solution is used instead of molality / as compared to other colligative properties its magnitude is large even for a very dilute solution.
(b) Solubility of oxygen is higher at a lower temperature.
(c) KCl being strong electrolyte dissociates into two moles of ions but sugar will not dissociate/ for KCl, \(\displaystyle \mathrm{i}=2\) and for sugar, \(\displaystyle \mathrm{i}=1\).
SolutionsColligative Properties and Determination of Molar MassUnderstandshort_answermedium
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CBSE Class 12 Chemistry past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.