Solutions Formulas - Chemistry Class 12

Learn important formulas from the Solutions chapter of Class 12 Chemistry with examples, variables and applications.

📐 Solutions Formulas

Complete collection of formulas with explanations and examples

Molarity

$$M = moles of solute / volume of solution in litre$$

Description: Molarity is a standard relation used in solutions.

Applications:

  • Use this when the quantities in the relation are known and the missing quantity is required.
  • Exam relevance: jee-main, jee-advanced, cuet, neet, bitsat, viteee, mht-cet, comedk-uget, wbjee, ap-eapcet, tg-eapcet, kcet, keam, gujcet, ojee, met, srmjeee, aeee, kiitee, iat, nest

Common Mistakes:

  • Using inconsistent units
  • Substituting values without checking the stated condition
JEE MAIN: high JEE ADVANCED: high CUET: high NEET: high BITSAT: high VITEEE: high MHT CET: high COMEDK UGET: high WBJEE: high AP EAPCET: high TG EAPCET: high KCET: high KEAM: high GUJCET: high OJEE: high MET: high SRMJEEE: high AEEE: high KIITEE: high IAT: high NEST: high

Molality

$$m = moles of solute / mass of solvent in kg$$

Description: Molality is a standard relation used in solutions.

Applications:

  • Use this when the quantities in the relation are known and the missing quantity is required.
  • Exam relevance: jee-main, jee-advanced, cuet, neet, bitsat, viteee, mht-cet, comedk-uget, wbjee, ap-eapcet, tg-eapcet, kcet, keam, gujcet, ojee, met, srmjeee, aeee, kiitee, iat, nest

Common Mistakes:

  • Using inconsistent units
  • Substituting values without checking the stated condition
JEE MAIN: high JEE ADVANCED: high CUET: high NEET: high BITSAT: high VITEEE: high MHT CET: high COMEDK UGET: high WBJEE: high AP EAPCET: high TG EAPCET: high KCET: high KEAM: high GUJCET: high OJEE: high MET: high SRMJEEE: high AEEE: high KIITEE: high IAT: high NEST: high

Mole Fraction

$$x_i = n_i / sum n_i$$

Description: Mole Fraction is a standard relation used in solutions.

Applications:

  • Use this when the quantities in the relation are known and the missing quantity is required.
  • Exam relevance: jee-main, jee-advanced, cuet, neet, bitsat, viteee, mht-cet, comedk-uget, wbjee, ap-eapcet, tg-eapcet, kcet, keam, gujcet, ojee, met, srmjeee, aeee, kiitee, iat, nest

Common Mistakes:

  • Using inconsistent units
  • Substituting values without checking the stated condition
JEE MAIN: high JEE ADVANCED: high CUET: high NEET: high BITSAT: high VITEEE: high MHT CET: high COMEDK UGET: high WBJEE: high AP EAPCET: high TG EAPCET: high KCET: high KEAM: high GUJCET: high OJEE: high MET: high SRMJEEE: high AEEE: high KIITEE: high IAT: high NEST: high

Raoult Law

$$p_i = x_i p_i^0$$

Description: Raoult Law is a standard relation used in solutions.

Applications:

  • Use this when the quantities in the relation are known and the missing quantity is required.
  • Exam relevance: jee-main, jee-advanced, cuet, neet, bitsat, viteee, mht-cet, comedk-uget, wbjee, ap-eapcet, tg-eapcet, kcet, keam, gujcet, ojee, met, srmjeee, aeee, kiitee, iat, nest

Common Mistakes:

  • Using inconsistent units
  • Substituting values without checking the stated condition
JEE MAIN: high JEE ADVANCED: high CUET: high NEET: high BITSAT: high VITEEE: high MHT CET: high COMEDK UGET: high WBJEE: high AP EAPCET: high TG EAPCET: high KCET: high KEAM: high GUJCET: high OJEE: high MET: high SRMJEEE: high AEEE: high KIITEE: high IAT: high NEST: high

Elevation in Boiling Point

$$Delta T_b = K_b m$$

Description: Elevation in Boiling Point is a standard relation used in solutions.

Applications:

  • Use this when the quantities in the relation are known and the missing quantity is required.
  • Exam relevance: jee-main, jee-advanced, cuet, neet, bitsat, viteee, mht-cet, comedk-uget, wbjee, ap-eapcet, tg-eapcet, kcet, keam, gujcet, ojee, met, srmjeee, aeee, kiitee, iat, nest

Common Mistakes:

  • Using inconsistent units
  • Substituting values without checking the stated condition
JEE MAIN: high JEE ADVANCED: high CUET: high NEET: high BITSAT: high VITEEE: high MHT CET: high COMEDK UGET: high WBJEE: high AP EAPCET: high TG EAPCET: high KCET: high KEAM: high GUJCET: high OJEE: high MET: high SRMJEEE: high AEEE: high KIITEE: high IAT: high NEST: high

Depression in Freezing Point

$$Delta T_f = K_f m$$

Description: Depression in Freezing Point is a standard relation used in solutions.

Applications:

  • Use this when the quantities in the relation are known and the missing quantity is required.
  • Exam relevance: jee-main, jee-advanced, cuet, neet, bitsat, viteee, mht-cet, comedk-uget, wbjee, ap-eapcet, tg-eapcet, kcet, keam, gujcet, ojee, met, srmjeee, aeee, kiitee, iat, nest

Common Mistakes:

  • Using inconsistent units
  • Substituting values without checking the stated condition
JEE MAIN: high JEE ADVANCED: high CUET: high NEET: high BITSAT: high VITEEE: high MHT CET: high COMEDK UGET: high WBJEE: high AP EAPCET: high TG EAPCET: high KCET: high KEAM: high GUJCET: high OJEE: high MET: high SRMJEEE: high AEEE: high KIITEE: high IAT: high NEST: high

Osmotic Pressure

$$pi = CRT$$

Description: Osmotic Pressure is a standard relation used in solutions.

Applications:

  • Use this when the quantities in the relation are known and the missing quantity is required.
  • Exam relevance: jee-main, jee-advanced, cuet, neet, bitsat, viteee, mht-cet, comedk-uget, wbjee, ap-eapcet, tg-eapcet, kcet, keam, gujcet, ojee, met, srmjeee, aeee, kiitee, iat, nest

Common Mistakes:

  • Using inconsistent units
  • Substituting values without checking the stated condition
JEE MAIN: high JEE ADVANCED: high CUET: high NEET: high BITSAT: high VITEEE: high MHT CET: high COMEDK UGET: high WBJEE: high AP EAPCET: high TG EAPCET: high KCET: high KEAM: high GUJCET: high OJEE: high MET: high SRMJEEE: high AEEE: high KIITEE: high IAT: high NEST: high

Van Hoff Factor

$$i = observed colligative property / normal colligative property$$

Description: Van Hoff Factor is a standard relation used in solutions.

Applications:

  • Use this when the quantities in the relation are known and the missing quantity is required.
  • Exam relevance: jee-main, jee-advanced, cuet, neet, bitsat, viteee, mht-cet, comedk-uget, wbjee, ap-eapcet, tg-eapcet, kcet, keam, gujcet, ojee, met, srmjeee, aeee, kiitee, iat, nest

Common Mistakes:

  • Using inconsistent units
  • Substituting values without checking the stated condition
JEE MAIN: high JEE ADVANCED: high CUET: high NEET: high BITSAT: high VITEEE: high MHT CET: high COMEDK UGET: high WBJEE: high AP EAPCET: high TG EAPCET: high KCET: high KEAM: high GUJCET: high OJEE: high MET: high SRMJEEE: high AEEE: high KIITEE: high IAT: high NEST: high

Quick Reference

Molarity: $M = moles of solute / volume of solution in litre$
Molality: $m = moles of solute / mass of solvent in kg$
Mole Fraction: $x_i = n_i / sum n_i$
Raoult Law: $p_i = x_i p_i^0$
Elevation in Boiling Point: $Delta T_b = K_b m$
Depression in Freezing Point: $Delta T_f = K_f m$
Osmotic Pressure: $pi = CRT$
Van Hoff Factor: $i = observed colligative property / normal colligative property$

💡 Worked Examples

Step-by-step solutions using Solutions formulas

Example 1: Area of Circle

Circle Area Formula
Problem:

Find the area of a circle with radius 7 cm.

Solution:
  1. Given: r = 7 cm
  2. Apply formula: A = πr²
  3. Substitute: A = π × 7²
  4. Calculate: A = π × 49 = 49π cm²
  5. Approximate: A ≈ 49 × 3.14159 ≈ 153.94 cm²
Answer:

Area = 49π cm² ≈ 153.94 cm²

🎯 Practice Problems

Try these problems to test your understanding:

Practice Problem 1

Solve the quadratic equation: x² - 7x + 12 = 0

Practice Problem 2

Find the area of a circle with diameter 14 cm.

Practice Problems

Check Your Formula Recall

Write each formula once, define every variable, then solve one direct substitution problem before moving to mixed questions.

Apply Solutions

Pick two formulas from this page and create your own values for the variables. Verify units and signs before calculating.

Derivation Notes

Focus on how the formula is built, not only the final expression. Derivations help with board-exam reasoning and multi-step application questions.

  • Start from the definition or identity used in the chapter.
  • Write assumptions clearly before substituting values.
  • Track units through each step to catch calculation mistakes.

Where These Formulas Are Used

Board Exam Problems

Use these formulas for direct numerical questions, proof-based steps, and short-answer reasoning in Chemistry.

Competitive Practice

Memorize the condition of use for each formula so you can identify the right expression quickly under timed practice.

Related Formula Chapters

Solutions 8 formulas Electrochemistry 4 formulas Chemical Kinetics 4 formulas Coordination Compounds 1 formulas Biomolecules 1 formulas

These Solutions formulas help students revise concepts quickly and apply equations accurately in exam-style problems.

Students Also Read

Keep learning

Discover More on SaralStudy

Explore all articles