CBSE 2025 · Region 5 · Set 1 · Q22 · 3 marks
Shweta mixed two liquids A and B of $\displaystyle 10$ mL each. After mixing, the volume of the solution was found to be $\displaystyle 20 \cdot 2 \mathrm{~mL}$.(i)Why was there a volume change after mixing the liquids ?(ii)Will there be an increase or decrease of temperature after mixing ?(iii)Give one example for this type of solution.(b)How does sprinkling of salt help in clearing the snow covered roads in hilly areas ?(ii)What happens when red blood cells are kept in $\displaystyle 0 \cdot 5 \%$ (mass/vol) NaCl solution ? Justify your answer.(iii)Write an application of reverse osmosis.
Shweta mixed two liquids A and B of $\displaystyle 10$ mL each. After mixing, the volume of the solution was found to be $\displaystyle 20 \cdot 2 \mathrm{~mL}$.
(i)
Why was there a volume change after mixing the liquids ?
(ii)
Will there be an increase or decrease of temperature after mixing ?
(iii)
Give one example for this type of solution.
(b)
How does sprinkling of salt help in clearing the snow covered roads in hilly areas ?
(ii)
What happens when red blood cells are kept in $\displaystyle 0 \cdot 5 \%$ (mass/vol) NaCl solution ? Justify your answer.
(iii)
Write an application of reverse osmosis.
Marking-scheme solution
(i)
The solution is non ideal, shows positive deviation from Raoult’s law / A-B interactions are
weaker than A-A and B-B interactions
(ii)
Decrease in temperature
(iii)
Ethanol and acetone
(i)
Salt lowers the freezing point of water and prevents formation of ice and hence its easy to
clean.
(ii)
-Red blood cells swell up
-As the solution is hypotonic, water will flow into the cell/ As the solution is hypotonic,
endosmosis occurs.
(iii)
Desalination of sea water
SolutionsIdeal and Non-ideal SolutionsUnderstandshort_answermedium
More from Solutions
- 0.3 g of acetic acid (M=60 g mol^-1) dissolved in 30 g of benzene shows a depression in freezing point equal…2023 · asked 6×
- Define molal depression constant. How is it related to enthalpy of fusion? OR What type of deviation is shown…2024 · asked 3×
- When a liquid and its vapour are at equilibrium and the pressure is suddenly decreased:2026 · asked 3×
- Explain the following with the help of Henry's law: (i) Bends (ii) Anoxia OR How does sprinkling of salt help…2026 · asked 3×
- Calculate the vapour pressure of a solution containing 61 g of benzoic acid (molar mass =122 g mol^-1 )…2026 · asked 3×
- The boiling point of one molal NaCl solution, assuming NaCl to be completely dissociated in water is: (K b.…2026 · asked 3×
- Give reasons: Cooking is faster in pressure cooker than in an open pan. On mixing liquid X and liquid Y,…2025 · asked 3×
- The colligative property used for the determination of molar mass of polymers and proteins is:2023 · asked 3×
CBSE Class 12 Chemistry past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.