Solutions — Class 12 Chemistry NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 12 Chemistry chapter "Solutions" — 8 important questions with detailed answers for CBSE board exam preparation.
✓ 100% Free
✓ No Login Needed
✓ NCERT / CBSE Aligned
✓ Download as PDF
TL;DR: Free step-by-step NCERT solutions for Class 12 Chemistry chapter "Solutions" — 8 important questions with detailed answers for CBSE board exam prepara…
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
🤖 Stuck on any question? Ask Syllab's free AI Tutor for a step-by-step explanation — instant, unlimited, no login.
Key Questions Covered:
- Define a solution. What are the main components of a solution?
- Calculate the molarity of a solution containing 10.6 g of Na₂CO₃ dissolved in…
- What is the difference between molarity and molality?
- State Henry's Law and explain its application.
- Calculate the mass of solute needed to prepare 500 mL of 0.1 M NaOH solution.
- Explain the process of osmosis and its importance in biological systems.
- + 2 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| Define a solution. What are the main components of a solu… | ✓ Solved |
| Calculate the molarity of a solution containing 10.6 g of… | ✓ Solved |
| What is the difference between molarity and molality? | ✓ Solved |
| State Henry's Law and explain its application. | ✓ Solved |
| Calculate the mass of solute needed to prepare 500 mL of … | ✓ Solved |
| Explain the process of osmosis and its importance in biol… | ✓ Solved |
Showing 6 of 8 questions
Q1: Define a solution. What are the main components of a solution?
A solution is a homogeneous mixture of two or more substances where one substance (solute) is uniformly dispersed in another (solvent).
Main components:
1. Solvent: The substance in which solute dissolves (usually present in larger amount). Typically liquid.
2. Solute: The substance being dissolved (present in smaller amount). Can be solid, liquid, or gas.
Example: In salt water, water is the solvent and salt (NaCl) is the solute.
Q2: Calculate the molarity of a solution containing 10.6 g of Na₂CO₃ dissolved in water to make 500 mL of solution.
Given: Mass of Na₂CO₃ = 10.6 g, Volume of solution = 500 mL = 0.5 L
Step 1: Calculate molar mass of Na₂CO₃
Molar mass = (2 × 23) + 12 + (3 × 16) = 46 + 12 + 48 = 106 g/mol
Step 2: Calculate number of moles
Moles = mass / molar mass = 10.6 / 106 = 0.1 mol
Step 3: Calculate molarity
Molarity = moles / volume (in L) = 0.1 / 0.5 = 0.2 M
Answer: Molarity = 0.2 M
Q3: What is the difference between molarity and molality?
Molarity (M):
1. Defined as moles of solute per litre of solution
2. Formula: M = moles / volume of solution (L)
3. Temperature dependent (volume changes with temperature)
4. Used in laboratory work and dilution calculations
Molality (m):
1. Defined as moles of solute per kilogram of solvent
2. Formula: m = moles / mass of solvent (kg)
3. Temperature independent (mass doesn't change with temperature)
4. Used for colligative properties and non-aqueous solutions
Example: A 1 M solution means 1 m...
Q4: State Henry's Law and explain its application.
Henry's Law states: The solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid, at a constant temperature.
Mathematical form:
p = K_H × x
where p = partial pressure of gas, x = mole fraction of gas in solution, K_H = Henry's law constant
Alternative form: S = K_H × p
where S = solubility of gas, p = partial pressure
Applications:
1. Carbonated beverages: CO₂ remains dissolved under pressure; fizzes when pressure is released
2. Scuba diving...
Q5: Calculate the mass of solute needed to prepare 500 mL of 0.1 M NaOH solution.
Given: Volume of solution = 500 mL = 0.5 L, Molarity = 0.1 M
Step 1: Calculate molar mass of NaOH
Molar mass = 23 + 16 + 1 = 40 g/mol
Step 2: Use molarity formula to find moles
Molarity = moles / volume (L)
0.1 = moles / 0.5
Moles = 0.1 × 0.5 = 0.05 mol
Step 3: Calculate mass of solute
Mass = moles × molar mass = 0.05 × 40 = 2 g
Answer: Mass of NaOH needed = 2 g
Q6: Explain the process of osmosis and its importance in biological systems.
Osmosis is the spontaneous flow of solvent molecules through a semipermeable membrane from a region of higher solvent concentration (lower solute concentration) to a region of lower solvent concentration (higher solute concentration).
Mechanism:
Solvent molecules move randomly; more pass through membrane in direction of lower solvent concentration, creating net flow of solvent.
Osmotic pressure (π):
π = CRT or π = iMRT
where C = molar concentration, R = gas constant, T = absolute temperature, ...
Showing 6 of 8 questions. Visit the full page for complete solutions.
More Class 12 Chemistry NCERT Solutions
- Electrochemistry — Class 12 Chemistry NCERT Solutions
- Chemical Kinetics — Class 12 Chemistry NCERT Solutions
- The D and F Block Elements — Class 12 Chemistry NCERT Solutions
- Coordination Compounds — Class 12 Chemistry NCERT Solutions
- Haloalkanes and Haloarenes — Class 12 Chemistry NCERT Solutions
- Alcohols Phenols and Ethers — Class 12 Chemistry NCERT Solutions
- Aldehydes Ketones and Carboxylic Acids — Class 12 Chemistry NCERT Solutions
- Amines — Class 12 Chemistry NCERT Solutions
- Biomolecules — Class 12 Chemistry NCERT Solutions