Explore topic-wise InterviewSolutions in .

The properties of solute which depend upon the number of particles present in definite amount of solvent but not on the chemical nature of solute are called colligative properties. 

They are-

(i) Relative lowering of vapour pressure 

(ii) Elevation in boiling point 

(iii) Depression in freezing point 

(iv) Osmotic pressure

Deep sea divers are advised not to come to surface immidiately from deep waters because sudden change in outside pressure can be fatal for divers because N₂ will bubble out of blood vessels causing severe pain and can be dangerous.

osmotic pressure is important in some vital biological systems.

Chloro benzene & bromo benzene is an ideal solution.

The mathematical expression of Raoult’s law is P_A = \(P^°_A\) . X_A

Helium, nitrogen and oxygen is used by deep-sea divers.

Common salt, sugar, acetic acid, sodium meta bisulfate. Overuse of salt causes hypertension (blood pressure). Use of sugar effects badly on diabetic patients. Acetic acid causes acidity.

1. False – Solutions which contain two components are called binary solution. 

2. False – In a solution the component which is present in lesser amount is called solute. 

3. False – Sodium chloride dissolved in water forms an aqueous solution. 

4. False – The molecular formula of green vitriol is FeSO₄ . 7H₂O 

5. True

Prepare a saturated solution of a solute like copper sulfate. When we allow it to evaporated slowly, the crystals are appeared. Select a suitable crystal and hang it in the solution with a twain. After a few days, the crystal can be seen grown as well.

A solution must at least be consisting of two components. Such solutions which are made of one solute and one solvent are called binary solutions. 

E.g., On adding CuSO₄ crystals to water.

A solution is a homogeneous mixture of two or more substances.

A solution containing a solute more than that required to form a saturated solution at equilibrium is called a supersaturated solution.

When a tiny crystal of a solute is added to supersaturated solution, the excess solute separates out and forms saturated solution.

(a) 40 g of NaCl

Prepare a saturated solution dissolving salt in water. Then the solution is heated and dissolves more solute in it

The solution obtained by dissolving maximum amount of solute at a given temperature is known as saturated solution. A solution which contains more amount of solute than that is required to saturate it is known as supersaturated solution.

(b) liquid in solid

(a) Sugar in water

(c) gas in liquid

An increase in pressure will increase the solubility of CO₂ gas.

11 g more salt is required for saturation

Mass percentage is expressed as w/w.

Hygroscopic substances are used as drying agents.

1. Saturated solution: A solution in which no more solute can be dissolved in a definite amount of the solvent at a given temperature is called saturated solution, e.g. 36 g of sodium chloride in 100 g of water at 25°C forms a saturated solution. 

2. Unsaturated solution: Unsaturated solution is one that contains less solute than that of the saturated solution at a given temperature, e.g. 10 g or 20 g or 30 g of Sodium chloride in 100 g of water at 25°C forms an unsaturated solution.

The capability of a solution to maintain a certain concentration of solute is temperature-dependent. When a saturated solution of copper sulphate at above room temperature is allowed to cool, the solution becomes supersaturated and in the absence of stirring or the return of the previous solution temperature, the solute starts to precipitate out. i.e., crystal formation occurs.

(c) silica gel

A. (iii) 

B. (iv) 

C. (v) 

D. (i) 

E. (ii)

The deliquescent substance among the following is CaCl₂ .

Nitrogen in soil is an example of a saturated solution in nature. Soil cannot store more Nitrogen than it can hold.

1. Solid in solid

2. liquid in solid 

3. liquid in liquid 

4. Gas in liquid

Answer: 5% 

Percentage of paracetamol = (( Mass of paracetamol) / (Volume of solution in ml)) x 100

\(=\frac{3}{60}\times100\) = 5%

1. Gas in liquid – CO₂ in water 

2. Solid in liquid – NaCl in water

3. Solid in solid – Alloys 

4. Gas in gas – He – O₂ gas

300 g of 25% solution contains solute = 75g 

400g of 40% solution contains solute = 160 g 

Total mass of solute = 160 + 75 = 235 g 

Total mass oÍ’ solution = 300 + 400 = 700 g 

% of solute in the final solution = \(\frac{235}{700}\) x 100 = 33.5% 

% of water in the finaI solution = 100 – 33.5 = 66.5%

6% \(\frac{v}{v}\) aqueous solution contains 6g of methanol in 100 ml solution. To prepare 500 ml of 6% \(\frac{v}{v}\) solution of methanol 30g methanol is taken in a 500 ml standard flask and required quantity of water is added to make up the solution to 500 ml.

Let the volume of 4M HCl required to prepare 500 mL of 2.5 M HCI = x mL

Therefore, the required volume of 2M HCI = (500 – x) mL

We know from the equation x = \(\frac{250}{2}\) = 125 mL 

Hence, volume of 4M HCI required = 125 mL

 Volume of 2M HCl required = (500 – 125) mL = 375 mL

1. A standard solution or a stock solution is a solution whose concentration is accurately known.

2. At the time of experiment, the solution with required concentration is prepared by diluting the stock solution. This diluted solution is called working standard.

Low concentration of oxygen in the blood and tissues of people living at high altitude is due to low atmospheric pressure

The properties which do not depend on the chemical nature of the solute but depends only on the number of solute particles present in the solution are called colligative properties. 

Example,

1. Relative lowering of vapour pressure – \(\frac{P°-P}{P°}\)

 2. Osmotic pressure – π 

3. Elevation of boiling point – ∆T_b

4. Depression in freezing point - ∆T_f

1. The boiling point of a liquid is the temperature at which its vapour pressure becomes equal to the atmospheric pressure.

2. When a non-volatile solute is added to pure solvent at its boiling point, the vapour pressure of the solution is lowered below 1 atm. To bring the vapour pressure again to 1 atm, the temperature of the solution has to be increased.

3. As a result, the solution boils at a higher temperature (T_b) then the boiling point of pure solvent (T_b°). This increase in the boiling point is known as elevation of boiling point.

1. The error due to weighing the solute can be minimised by using concentrated stock solution that requires large quantities of solute.

2. We can prepare working standards of different concentrations by diluting the stock solution which is more efficient since consistency is maintained.

3. Some of the concentrated solutions are more stable and are less likely to support microbial growth than working standards used in the experiments.

1. A solution is a homogeneous mixture of two or more substances, consisting of atoms. ions or molecules. 

2. Types and examples of solution.

A. (iv) 

B. (iii) 

C. (v) 

D. (ii) 

E. (i)