10-Day Revision Plan

Chemical Reactions & Equations + Acids, Bases and Salts

Day 1 — Chemical Equations Basics

Writing and balancing chemical equations (hit-and-trial method)
Word equations → symbol equations
Types of reactions: Combination & Decomposition
- Sub-types of decomposition: thermal, electrolytic, photolytic
Practice: Balance 15–20 equations from NCERT

Day 2 — More Reaction Types

Displacement and Double Displacement reactions
Precipitation reactions (identify precipitate formation)
Oxidation & Reduction — definitions in terms of gain/loss of oxygen and hydrogen
Redox reactions — identify oxidised/reduced species in given equations
Practice: Identify reaction type for 20 mixed equations

Day 3 — Everyday Applications

Effects of oxidation in daily life: Corrosion and Rancidity
Ways to prevent rancidity (antioxidants, airtight containers, refrigeration, nitrogen flushing)
Quick revise Day 1 & 2 concepts (10 min flash recall, no notes)
Solve 5 previous-year/HOTS questions

Day 4 — Full Revision: Chapter 1

Complete NCERT in-text + end-of-chapter questions
Make a one-page equation/keyword cheat sheet
Self-test: 15 MCQs + 5 short-answer questions (timed, 30 min)

Day 5 — Acids and Bases: Properties

Chemical properties of acids and bases
Reaction of acids/bases with metals (H₂ gas test)
Reaction with metal carbonates/bicarbonates (CO₂ test)
Reaction of acids with bases (neutralization)
Natural, synthetic, and olfactory indicators (litmus, turmeric, onion/vanilla)

Day 6 — pH Concept

pH scale (0–14), pH paper vs universal indicator
Relation between H⁺ ion concentration and pH
Importance of pH in everyday life:
- Human body (stomach acid, tooth decay)
- Plants and animals (soil pH, aquatic life)
- Digestion (antacids)
Practice pH-based numericals/diagram questions

Day 7 — Salts (Part 1)

Family of salts, pH of salt solutions (acidic/basic/neutral salt)
Common salt (NaCl) — preparation & uses
Chlor-alkali process → NaOH, Cl₂, H₂ and their uses
Bleaching powder — preparation, formula (CaOCl₂), uses

Day 8 — Salts (Part 2)

Baking soda (NaHCO₃) — preparation, uses, reaction on heating
Washing soda (Na₂CO₃·10H₂O) — preparation from baking soda, uses
Plaster of Paris (CaSO₄·½H₂O) — preparation, setting reaction, uses
Water of crystallization — concept + examples (gypsum, blue vitriol)
Revise Day 5–7 with a self-made table (salt | formula | prep | uses)

Day 9 — Full Revision: Both Chapters

Redo all equations from both chapters without looking (write from memory)
Diagram practice: activity setups (e.g., zinc + acid, rusting experiment)
Solve previous year board questions (both chapters mixed)
List down formulas/definitions still shaky — mark for Day 10

Day 10 — Mock Test + Final Touch-Up

Take a full mock test (1 hour): mix of MCQs, short answer, long answer, HOTS
Evaluate and identify weak spots
Rapid-fire revision of:
- All reaction types with examples
- All salt formulas and uses
- pH values of common substances
Final cheat-sheet read-through (both chapters, 20–30 min)

Daily Tips

Spend the last 10 minutes of each day writing 5 equations from memory.
Keep a single running list of "confusing points" — review it every 2 days.
Use active recall (self-quiz) over passive re-reading wherever possible.

Chapter: Acids, Bases and Salts

Class: X | Subject: Science (Chemistry)

Time Allowed: 40 minutes Maximum Marks: 20

General Instructions:

(i) All questions are compulsory.

(ii) Questions 1–3 are Multiple Choice Questions (1 mark each).

(iii) Questions 4–5 are Assertion–Reason type (1 mark each).

(iv) Questions 6–7 carry 2 marks; 8–9 carry 3 marks; Question 10 carries 5 marks.

(v) All questions are based on real-life/competency-based scenarios — read each carefully before answering.

Section A — Multiple Choice Questions (1 × 3 = 3 marks)

1. A student spills a few drops of a colourless liquid on the lab bench. On testing with blue and red litmus paper, the blue litmus turns red but the red litmus shows no change. The liquid is most likely:

(a) A basic solution such as dilute NaOH

(b) An acidic solution such as dilute HCl

(d) Distilled water

2. Ravi adds a pinch of baking soda to a test tube containing dilute acetic acid. He observes brisk effervescence. When he passes the gas produced through freshly prepared lime water, it turns milky. The gas evolved is:

(a) Hydrogen gas

(b) Oxygen gas

(d) Sulphur dioxide gas

3. A farmer is advised to treat his acidic soil before sowing crops. Which of the following would he most appropriately add to the soil to neutralise its excess acidity?

(a) Quick lime (calcium oxide)

(b) Gypsum

(d) Sulphuric acid

Section B — Assertion–Reason Type (1 × 2 = 2 marks)

For questions 4 and 5, two statements are given — one labelled Assertion (A) and the other labelled Reason (R). Choose the correct option:

(a) Both A and R are true, and R is the correct explanation of A.

(b) Both A and R are true, but R is not the correct explanation of A.

(d) A is false, but R is true.

4. Assertion (A): Dilute acids are generally stored and transported in plastic containers rather than metal containers.

Reason (R): Acids react with reactive metals to liberate hydrogen gas, which can corrode a metal container over time.

5. Assertion (A): While diluting a concentrated acid, the acid should always be added slowly to water, and not water to acid.

Reason (R): The process of dissolving an acid in water is highly exothermic, and adding water to concentrated acid can cause the mixture to splash out due to sudden local heating.

Section C — Short Answer Type I (2 × 2 = 4 marks)

6. A shopkeeper stores an antacid tablet on his shelf to treat acidity. A customer complains of a burning sensation in the stomach after a heavy meal and asks how the tablet works.

Explain, with a chemical equation, how an antacid tablet (containing milk of magnesia) relieves acidity. Name the type of reaction involved.

7. Two test tubes, A and B, contain colourless solutions. A student adds a few drops of phenolphthalein to test tube A and it turns pink; the same indicator added to test tube B shows no colour change.

Identify the nature (acidic/basic/neutral) of the solution in each test tube. Justify your answer using the property of phenolphthalein.

Section D — Short Answer Type II (3 × 2 = 6 marks)

8. A milkman adds a very small amount of baking soda to fresh milk before storing it for a few hours in summer, to prevent it from turning sour quickly.

(a) State whether baking soda is acidic, basic or neutral in nature.

(b) Explain how adding it shifts the pH of milk and helps delay souring. (c) Write the chemical name and formula of baking soda.

9. During an experiment, a student takes dilute sulphuric acid in a test tube and drops a few pieces of zinc granules into it. She observes bubbles of a gas forming, and on bringing a burning matchstick near the mouth of the test tube, it burns with a 'pop' sound.

(a) Identify the gas evolved and write a balanced chemical equation for the reaction.

(b) Why does the gas burn with a pop sound?

(c) Name one metal that would NOT show this reaction with dilute acids, and give a reason.

Section E — Long Answer Type (5 × 1 = 5 marks)

10. A water-treatment plant supervisor needs to make chlorine-free drinking water safe for a village that primarily has hard, slightly acidic water. He plans to use bleaching powder for disinfection and lime for treating the acidity of water and soil around the reservoir.

(a) Name the chemical compound used as bleaching powder, and write the chemical equation for its preparation from slaked lime.

(b) Explain why bleaching powder is used for disinfecting drinking water.

(c) Name the type of lime used to reduce soil/water acidity and write its chemical formula.

(d) A student says, 'Plaster of Paris and bleaching powder are prepared from the same raw material.' Justify whether this statement is correct, identifying the common raw material.

(e) State one precaution that should be taken while storing bleaching powder.

— End of Question Paper —

Cbse guide

Wednesday, August 5, 2026

Revision Schedule grade 10 chemistry