10 simple and important numericals from the Chapter: Solutions (Class 12 Chemistry) based on CBSE board exam pattern, designed to build clarity on key concepts:
1.
Calculate the molarity of a solution prepared by dissolving 5.8 g of NaCl in 500 mL of solution.
(Molar mass of NaCl = 58.5 g/mol)
2.
Find the molality of a solution containing 36 g of glucose (C₆H₁₂O₆) dissolved in 250 g of water.
(Molar mass of glucose = 180 g/mol)
3.
Calculate the mass of urea (NH₂CONH₂) required to be dissolved in 100 g of water to lower the freezing point by 0.93°C.
(Kf for water = 1.86 K kg/mol; Molar mass of urea = 60 g/mol)
4.
Determine the boiling point of a solution containing 1.0 mol of a non-volatile solute in 1.0 kg of water.
(Kb for water = 0.52 K kg/mol; Normal boiling point of water = 373 K)
5.
A solution is prepared by dissolving 10 g of a non-electrolyte solute in 200 g of water. The boiling point of solution is 100.26°C. Calculate the molar mass of solute.
(Kb = 0.52 K kg/mol)
6.
Calculate the osmotic pressure of a 0.1 M solution of sucrose at 27°C.
(R = 0.0821 L·atm/mol·K)
7.
The vapour pressure of pure benzene at a certain temperature is 100 mm Hg. A non-volatile solute is added and the vapour pressure drops to 95 mm Hg. Calculate the mole fraction of solute.
8.
Find the mass of NaCl to be dissolved in 500 g of water to produce a solution having a freezing point of -1.86°C.
(Kf for water = 1.86 K kg/mol; Molar mass of NaCl = 58.5 g/mol; i = 2)
9.
Calculate the mole fraction of ethanol in a solution containing 46 g of ethanol (C₂H₅OH) and 180 g of water.
(Molar mass: Ethanol = 46 g/mol, Water = 18 g/mol)
10.
A 5% (w/v) solution of a substance exerts an osmotic pressure of 4.1 atm at 27°C. Calculate the molar mass of the solute.
(R = 0.0821 L·atm/mol·K)
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