MCQ Questions for Class 10 Science Chapter 1 Chemical Reactions and Equations

MCQ Questions for Class 10 Science Chapter 1 Chemical Reactions and Equations help to identify the areas where the students need more work. This type of question is often used in exams, and practicing with them can help you get the highest marks possible.

Chapter 1 Class 10 Science MCQ Questions also helpful for the students who want to improve their time management skills. They help to improve problem solving skills and promote active learning.

Chapter 1 Chemical Reactions and Equations Class 10 Science MCQ Questions

1. Which one of the following processes involve chemical reactions?
(a) Storing of oxygen gas under pressure in a gas cylinder
(b) Liquefaction of air
(c) Keeping petrol in a china dish in the open
(d) Heating copper wire in presence of air at high temperature
▶ (d) Heating copper wire in presence of air at high temperature

2. Which of the following reactions represents a combination reaction?
(a) CaO (s) + H₂O (l) → Ca(OH)₂ (aq)
(b) CaCO₃ (s) → CaO(s) + CO₂ (g)
(c) Zn(s) + CuSO₄ (aq) → ZnSO₄ (aq) + Cu (s)
(d) 2FeSO₄ (s) → FeO₃(s) + SO₂ (g) + SO₃(g)
▶ (a) CaO (s) + H₂O (l) → Ca(OH)₂ (aq)

3. Dilute hydrochloric acid is added to granulated zinc taken in a test tube. The following observations are recorded. Point out the correct observation.
(a) The surface of metal becomes shining
(b) The reaction mixture turns milky
(c) Odour of a pungent smelling gas is recorded
(d) A colourless and odourless gas is evolved
▶ (d) A colourless and odourless gas is evolved

4. When crystals of lead nitrate are heated strongly in a dry test tube
(a) crystals immediately melt
(c) white fumes appear in the tube
(b) a brown residue is left
(d) a yellow residue is left
▶ (d) a yellow residue is left

5. In which of the following, heat energy will be evolved?
(a) Burning of LPG
(b) Dissolution of NH₄Cl in water
(c) Electrolysis of water
(d) Decomposition of AgBr in the presence of sunlight
(d) pink
▶ (a) Burning of LPG

6. Oxidation is a process which involves
(a) addition of oxygen
(b) addition of hydrogen
(c) removal of oxygen
(d) removal of hydrogen
▶ (a) addition of oxygen

7. When carbon dioxide is passed through lime water
(a) calcium hydroxide is formed
(c) lime water turns milky
(b) white precipitate of CaO is formed
(d) colour of lime water disappears.
▶ (b) white precipitate of CaO is formed

8. The process of reduction involves
(a) addition of oxygen
(b) addition of hydrogen
(c) removal of oxygen
(d) removal of hydrogen
▶ (b) addition of hydrogen

9. The electrolytic decomposition of water gives H₂ and O₂ in the ratio of
(a) 2:1 by volume
(b) 1:2 by volume
(c) 8:1 by mass
(d) 1:2 by mass
▶ (a) 2:1 by volume

10. In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate?
(a) Lead sulphate (insoluble)
(b) Lead acetate
(c) Ammonium nitrate
(d) Potassium sulphate
▶ (b) Lead acetate

11. Which of the following gases can be used for storage of fresh sample of an oil for a long time?
(a) Carbon dioxide or oxygen
(b) Nitrogen or helium
(c) Helium or oxygen
(d) Nitrogen or oxygen
▶ (b) Nitrogen or helium

12. Fatty foods become rancid due to the process of
(a) reduction
(b) corrosion
(c) oxidation
(d) hydrogenation
▶ (c) oxidation

13. What type of chemical reactions take place when electricity is passed through water?
(a) Displacement
(b) Combination
(c) Decomposition
(d) Double displacement
▶ (c) Decomposition

14. On immersing an iron nail in CuSO₄ solution for few minutes, you will observe
(a) no reaction takes place
(b) the colour of solution changes to green
(c) the surface of iron nails acquire a black coating
(d) the colour of solution fades away
▶ (b) the colour of solution changes to green

15. A substance added to food containing fats and oils is called:
(a) Oxidant
(b) Rancid
(c) Coolant
(d) Antioxidant
▶ (d) Antioxidant

16. The reaction in which two compounds exchange their ions to form two new compounds is called
(a) displacement reaction
(c) double displacement reaction
(b) combination reaction
(d) redox reaction
▶ (b) combination reaction

17. The condition produced by aerial oxidation of fats and oils in foods marked by unpleasant smell and taste is called:
(a) antioxidation
(b) reduction
(c) rancidity
(d) corrosion
▶ (c) rancidity

18. Which of the following does show oxidation reaction?
(a) Gain of oxygen
(c) Gain of hydrogen
(b) Loss of oxygen
(d) None of the above
▶ (a) Gain of oxygen

19. Which of the following is an endothermic process?
(a) Dilution of sulphuric acid
(b) Sublimation of dry ice
(c) Condensation of water vapours
(d) Respiration in human beings
▶ (b) Sublimation of dry ice

20. In which of the following heat is absorbed generally?
(a) Combination reaction
(b) Decomposition reaction
(c) Displacement reaction
(d) Double displacement reaction
▶ (b) Decomposition reaction

21. Which of the following termed as reducing agent?
(a) Which gives oxygen
(c) Which removes hydrogen
(b) Which removes oxygen
(d) All of the above
▶ (c) Which removes hydrogen

22. When Ag is exposed to air it gets a black coating of
(a) AgNO₃
(b) Ag₂S
(c) Ag₂O
(d) Ag₂CO₃
▶ (b) Ag₂S

23. In which of the following heat is evolved?
(a) Combination reaction
(c) Displacement reaction
(b) Decomposition reaction
(d) Oxidation reaction
▶ (a) Combination reaction

24. Which of the following is termed as exothermic reaction?
(b) Reaction in which heat is absorbed
(a) Reaction in which heat is evolved
(c) Reaction in which there is loss of oxygen
(d) Reaction in which there is gain of hydrogen
▶ (b) Reaction in which heat is absorbed

25. What happens when dilute hydrochloric acid is added to iron filings?
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
▶ (a) Hydrogen gas and iron chloride are produced.

26. Which of the following is termed as endothermic reaction?
(a) Reaction in which heat is evolved
(b) Reaction in which heat is absorbed
(c) Reaction in which there is loss of oxygen
(d) Reaction in which there is gain of hydrogen
▶ (b) Reaction in which heat is absorbed

27. A balanced chemical equation is in accordance with
(a) Avogadro’s law
(b) law of multiple proportion
(c) law of conservation of mass
(d) law of gaseous volumes
▶ (c) law of conservation of mass

28. What happens when silver bromide is exposed to sunlight?
(a) Hydrogen gas is formed
(c) Chlorine gas is formed
(b) Bromine gas is formed
(d) Iodine gas is formed
▶ (c) Chlorine gas is formed

29. In which of the following category will you put the reaction of heating of calcium carbonate?
(a) Decomposition reaction
(c) Endothermic reaction
(b) Thermal decomposition reaction
(d) All of the above
▶ (d) All of the above

30. What happens when carbon dioxide is passed through lime water?
(a) Lime water turns milky because of formation of calcium carbonate
(b) Lime water turns milky because of formation of water
(c) Lime water turns red because of formation of permanganate
(d) Lime water turns red because of formation of copper sulphate
▶ (a) Lime water turns milky because of formation of calcium carbonate