125 Short question answers of Chemistry Chaper-1 Solution

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Class 12 Quizzes Revision Notes

Physical Chemistry Master Series

Solutions Master Q&A

Strictly preserving every sentence from the original source. 125 points covering Classification, Laws, Azeotropes, and Colligative Properties.

Classification (1-25) Henry & Raoult (1-25) Ideal/Non-Ideal (1-25) Azeotropes (1-25) Colligative (1-25)

1. Solutions and Their Classification (25 Q&A)

No.	Question	Answer
1	What is a solution?	A solution is a homogeneous mixture of two or more substances.
2	What is a solute?	The substance that is dissolved in a solution is called the solute.
3	What is a solvent?	The substance that dissolves the solute is called the solvent.
4	Give an example of a solid in liquid solution.	Salt in water.
5	Give an example of a gas in liquid solution.	Carbon dioxide in soda water.
6	What is a liquid in liquid solution?	Alcohol in water is an example.
7	Name a gas in gas solution.	Air (oxygen in nitrogen).
8	What is a solid in solid solution?	Alloys like brass (zinc in copper).
9	How are solutions classified based on physical state?	Into solid, liquid, and gaseous solutions.
10	What are dilute solutions?	Solutions with a small amount of solute.
11	What are concentrated solutions?	Solutions with a large amount of solute.
12	What is a saturated solution?	A solution in which no more solute can dissolve at a given temperature.
13	What is an unsaturated solution?	A solution that can dissolve more solute at the same temperature.
14	What is a supersaturated solution?	A solution that contains more solute than it can hold at that temperature.
15	What is meant by the concentration of a solution?	The amount of solute present in a given quantity of solvent or solution.
16	How can you express concentration?	In terms of percentage, molarity, molality, and normality.
17	What is molarity?	Moles of solute per litre of solution.
18	What is molality?	Moles of solute per kg of solvent.
19	What is normality?	Gram equivalents of solute per litre of solution.
20	What is mass percentage?	(Mass of solute / Mass of solution) $\times$ 100.
21	What is volume percentage?	(Volume of solute / Volume of solution) $\times$ 100.
22	What is mole fraction?	Ratio of moles of one component to total moles of all components.
23	What affects the solubility of a solute?	Temperature, pressure, and nature of solute and solvent.
24	How does temperature affect solubility?	For most solids, solubility increases with temperature.
25	How does pressure affect solubility of gases?	Solubility of gases increases with pressure (Henry's law).

2. Henry's Law and Raoult's Law (25 Q&A)

No.	Question	Answer
1	What is Henry's Law?	It states that the solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid.
2	Give the mathematical expression of Henry's Law.	$C = kP$, where C is solubility, k is Henry’s constant, and P is pressure.
3	What does Henry's constant (k) signify?	It indicates the solubility of a gas at a particular pressure.
4	How does temperature affect Henry's constant?	Henry’s constant increases with temperature, meaning gas solubility decreases.
5	Name a real-life application of Henry’s Law.	Carbonated beverages are bottled under high pressure to increase $CO_2$ solubility.
6	How is Henry’s Law used in scuba diving?	It helps explain nitrogen narcosis; high pressure causes more nitrogen to dissolve in the blood.
7	What happens to gases at high altitudes based on Henry’s Law?	Lower pressure causes gases like oxygen to dissolve less in blood, leading to altitude sickness.
8	How does Henry's Law relate to respiration in humans?	It explains the exchange of oxygen and carbon dioxide in the lungs based on partial pressures.
9	What is Raoult's Law?	It states that the partial vapor pressure of a component in a solution is directly proportional to its mole fraction.
10	Give the formula for Raoult's Law.	$P_1 = X_1P_1^0$, where $P_1$ is the partial vapor pressure, $X_1$ is mole fraction, and $P_1^0$ is vapor pressure of pure solvent.
11	What is an ideal solution?	A solution that obeys Raoult’s law at all concentrations and temperatures.
12	Give an example of an ideal solution.	Benzene and toluene mixture.
13	What is a non-ideal solution?	A solution that deviates from Raoult's law due to differences in intermolecular forces.
14	What is positive deviation from Raoult’s law?	When the vapor pressure is greater than predicted, due to weaker intermolecular forces.
15	Give an example of positive deviation.	Ethanol and acetone.
16	What is negative deviation from Raoult’s law?	When the vapor pressure is lower than predicted, due to stronger intermolecular forces.
17	Give an example of negative deviation.	Chloroform and acetone.
18	What is total vapor pressure of a solution?	It is the sum of partial vapor pressures of all components.
19	How is total vapor pressure calculated in a binary solution?	$P_{total} = X_1P_1^0 + X_2P_2^0$.
20	What is Dalton’s Law of Partial Pressures?	The total pressure exerted by a mixture of gases is the sum of the partial pressures.
21	How is Raoult's law related to Dalton’s law?	Raoult's law provides partial pressures in liquid mixtures, which can be summed using Dalton’s law.
22	What is relative lowering of vapor pressure?	It is the decrease in vapor pressure when a non-volatile solute is added to a solvent.
23	How does Raoult’s Law help determine molar mass?	By measuring vapor pressure lowering, molar mass of a solute can be calculated.
24	What is the effect of a non-volatile solute on vapor pressure?	It lowers the vapor pressure of the solvent.
25	How is Raoult’s law important in colligative properties?	It explains phenomena like boiling point elevation and freezing point depression.

3. Ideal & Non-Ideal Solutions, Azeotropes (25 Q&A)

No.	Question	Answer
1	What is an ideal solution?	A solution that obeys Raoult’s law over the entire composition range.
2	What are the characteristics of an ideal solution?	No enthalpy change ($\Delta H_{mix} = 0$) and no volume change ($\Delta V_{mix} = 0$) on mixing.
3	Give an example of an ideal solution.	Benzene and toluene.
4	What is a non-ideal solution?	A solution that does not obey Raoult’s law over the entire composition range.
5	What are the types of non-ideal solutions?	Positive deviation and negative deviation from Raoult’s law.
6	What is positive deviation from Raoult's Law?	When the total vapor pressure is more than expected due to weaker intermolecular forces.
7	Give an example of a solution showing positive deviation.	Ethanol and acetone.
8	What is negative deviation from Raoult's Law?	When the total vapor pressure is less than expected due to stronger intermolecular forces.
9	Give an example of a solution showing negative deviation.	Chloroform and acetone.
10	What causes deviation in non-ideal solutions?	Different strength of intermolecular forces between solute and solvent.
11	What is an azeotrope?	A constant boiling mixture of two or more liquids that behaves like a single substance.
12	Why are azeotropes called constant boiling mixtures?	Because they boil at a constant temperature without change in composition.
13	What are the types of azeotropes?	Minimum boiling azeotropes and maximum boiling azeotropes.
14	What is a minimum boiling azeotrope?	A mixture that boils at a lower temperature than either component.
15	Give an example of a minimum boiling azeotrope.	Ethanol and water (95% ethanol).
16	What is a maximum boiling azeotrope?	A mixture that boils at a higher temperature than either component.
17	Give an example of a maximum boiling azeotrope.	Hydrochloric acid and water (20% HCl).
18	Why can't azeotropes be separated by simple distillation?	Because they vaporize without change in composition.
19	How are azeotropes separated?	Using special techniques like azeotropic distillation or adding a third component.
20	How does Raoult’s law explain azeotrope formation?	Azeotropes form due to large deviations from Raoult’s law.
21	What is the composition of an azeotrope dependent on?	It depends on the nature of the components and temperature.
22	Are azeotropes ideal or non-ideal solutions?	They are non-ideal solutions.
23	What is meant by constant composition distillation?	Distillation where the vapor and liquid phases have the same composition, as in azeotropes.
24	Can azeotropes be binary or ternary?	Yes, they can be made up of two (binary) or more (ternary) components.
25	Why are azeotropes important in industry?	They affect the purity and separation of chemicals in industrial distillation processes.

4. Ideal & Non-Ideal Solutions, Azeotropes - Continued (25 Q&A)

No.	Question	Answer
1	What is an ideal solution?	A solution that obeys Raoult’s law over the entire composition range.
2	What are the characteristics of an ideal solution?	No enthalpy change ($\Delta H_{mix} = 0$) and no volume change ($\Delta V_{mix} = 0$) on mixing.
3	Give an example of an ideal solution.	Benzene and toluene.
4	What is a non-ideal solution?	A solution that does not obey Raoult’s law over the entire composition range.
5	What are the types of non-ideal solutions?	Positive deviation and negative deviation from Raoult’s law.
6	What is positive deviation from Raoult's Law?	When the total vapor pressure is more than expected due to weaker intermolecular forces.
7	Give an example of a solution showing positive deviation.	Ethanol and acetone.
8	What is negative deviation from Raoult's Law?	When the total vapor pressure is less than expected due to stronger intermolecular forces.
9	Give an example of a solution showing negative deviation.	Chloroform and acetone.
10	What causes deviation in non-ideal solutions?	Different strength of intermolecular forces between solute and solvent.
11	What is an azeotrope?	A constant boiling mixture of two or more liquids that behaves like a single substance.
12	Why are azeotropes called constant boiling mixtures?	Because they boil at a constant temperature without change in composition.
13	What are the types of azeotropes?	Minimum boiling azeotropes and maximum boiling azeotropes.
14	What is a minimum boiling azeotrope?	A mixture that boils at a lower temperature than either component.
15	Give an example of a minimum boiling azeotrope.	Ethanol and water (95% ethanol).
16	What is a maximum boiling azeotrope?	A mixture that boils at a higher temperature than either component.
17	Give an example of a maximum boiling azeotrope.	Hydrochloric acid and water (20% HCl).
18	Why can't azeotropes be separated by simple distillation?	Because they vaporize without change in composition.
19	How are azeotropes separated?	Using special techniques like azeotropic distillation or adding a third component.
20	How does Raoult’s law explain azeotrope formation?	Azeotropes form due to large deviations from Raoult’s law.
21	What is the composition of an azeotrope dependent on?	It depends on the nature of the components and temperature.
22	Are azeotropes ideal or non-ideal solutions?	They are non-ideal solutions.
23	What is meant by constant composition distillation?	Distillation where the vapor and liquid phases have the same composition, as in azeotropes.
24	Can azeotropes be binary or ternary?	Yes, they can be made up of two (binary) or more (ternary) components.
25	Why are azeotropes important in industry?	They affect the purity and separation of chemicals in industrial distillation processes.

5. Colligative Properties (25 Q&A)

No.	Question	Answer
1	What are colligative properties?	Properties that depend on the number of solute particles and not on their nature.
2	Name the four main colligative properties.	Relative lowering of vapor pressure, elevation of boiling point, depression of freezing point, and osmotic pressure.
3	What is relative lowering of vapor pressure?	The decrease in vapor pressure of a solvent due to the addition of a non-volatile solute.
4	Write the formula for relative lowering of vapor pressure.	$(P_0 - P) / P_0 = n_2 / (n_1 + n_2)$, where $P_0$ = vapor pressure of pure solvent, $P$ = solution, $n_1$ = moles of solvent, $n_2$ = moles of solute.
5	What is elevation of boiling point?	The increase in boiling point of a solvent when a non-volatile solute is added.
6	What is the formula for elevation of boiling point?	$\Delta T_b = K_b \times m$, where $K_b$ is the ebullioscopic constant and $m$ is molality.
7	What is depression of freezing point?	The decrease in freezing point of a solvent due to a non-volatile solute.
8	What is the formula for depression of freezing point?	$\Delta T_f = K_f \times m$, where $K_f$ is the cryoscopic constant and $m$ is molality.
9	What is osmotic pressure?	The pressure required to stop the flow of solvent into a solution through a semipermeable membrane.
10	What is the formula for osmotic pressure?	$\Pi = CRT$, where C = concentration, R = gas constant, T = temperature.
11	What is a semipermeable membrane?	A membrane that allows only solvent molecules to pass through, not solute particles.
12	What is osmosis?	The movement of solvent molecules through a semipermeable membrane from a dilute to a concentrated solution.
13	What is reverse osmosis?	Forcing solvent through a semipermeable membrane from concentrated to dilute side by applying pressure greater than osmotic pressure.
14	How is molar mass determined using colligative properties?	By measuring the extent of a colligative property like $\Delta T_f$, $\Delta T_b$, $\Pi$, or vapor pressure lowering.
15	What is the van’t Hoff factor (i)?	The ratio of actual number of particles in solution after dissociation or association to the number of formula units initially dissolved.
16	Write the formula for van’t Hoff factor.	$i = \text{Normal colligative property} / \text{Observed colligative property}$.
17	What is the effect of dissociation on colligative properties?	It increases the number of particles, thus increasing the effect.
18	What is the effect of association on colligative properties?	It decreases the number of particles, thus decreasing the effect.
19	What kind of solutes affect colligative properties?	Only non-volatile solutes affect colligative properties.
20	Why are colligative properties called colligative?	Because they depend on the “collection” or number of solute particles.
21	How does ionic solute affect colligative properties?	Ionic solutes dissociate into multiple particles, increasing the colligative effect.
22	Give an example where colligative property helps in real life.	Adding salt to icy roads lowers the freezing point of water.
23	Which property is used in determining the molar mass of proteins?	Osmotic pressure.
24	Why is osmotic pressure preferred for molar mass of biomolecules?	Because it can be measured accurately even at low concentrations.
25	What is abnormal molar mass?	Molar mass determined from colligative properties that deviates due to association or dissociation of solute particles.

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