CBSE Class 10 Science Multiple Choice Questions(MCQs) & Answers

1 The non-metal which is liquid at room temperature is:

A Bromine

B Helium

C Mercury

D Carbon

View Answer

Answer: Bromine

2 Ester is formed by the reaction between:

A An acid and an alcohol

B An acid and an alkene

C An acid and a base

D A base and an alcohol

View Answer

Answer: An acid and an alcohol

3 The number of protons in an atom of an element A is 19 then, the number of electron in its ion A+ is:

A 21

B 19

C 18

D 20

View Answer

Answer: 18

4 Bauxite is an ore of

A Iron

B Aluminium

C Mercury

D Copper

View Answer

Answer: Aluminium

5 The metal which is liquid at room temperature is

A Mercury

B Potassium

C Bromine

D Iodine

View Answer

Answer: Mercury

6 The sulphide ores are converted into oxides by heating strongly in the presence of excess air. This process is known as

A Refining

B Roasting

C Smelting

D Calcination

View Answer

Answer: Roasting

7 In electrolytic refining, the cathode is made up of

A Metallic salt

B Pure metal

C Impure metal

D None of these

View Answer

Answer: Pure metal

8 In the given reaction, Al2O3 + NaOH → ……X…… + H2O What is element X?

A NaAlO2

B NaAl2O3

C Na3Al

D Na2O3

View Answer

Answer: NaAlO2

9 Which of the following represent the correct order of decreasing reactivity?

A Mg > Al > Zn > Fe

B Mg > Fe > Zn > Al

C Mg > Zn > Al > Fe

D Al > Zn > Fe > Mg

View Answer

Answer: Mg > Al > Zn > Fe

10 An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be

A Fe

B Ca

C C

D None of these

View Answer

Answer: Ca

11 Which of the following pairs will give displacement reactions?

A AgNO3 solution and copper metal

B FeSO4 solution and silver metal

C NaCl solution and copper metal

D MgCl2 solution and aluminium metal

View Answer

Answer: AgNO3 solution and copper metal

12 Which among the following is the most abundant metal found in the earth’s crust?

A Aluminium

B Iron

C Magnesium

D Oxygen

View Answer

Answer: Aluminium

13 Which of the following pairs of reactants will go undergo a displacement reaction?

A Ca(SO4)2 + Fe

B CuSO4 + Fe

C ZnSO4 + Fe

D MgSO4 + Fe

View Answer

Answer: CuSO4 + Fe

14 Galvanisation is a method of protecting steel and iron from rusting by coating them with a thin layer of

A Zinc

B Bauxite

C Copper

D Aluminum

View Answer

Answer: Zinc

15 Which of the following alloys contains a non-metal as one of its constituents?

A Bronze

B Brass

C Steel

D Amalgam

View Answer

Answer: Steel

16 An element X is soft and can be cut with the help of a knife. It is very reactive to air and cannot be kept open in the air. It reacts vigorously with water. Identify the element from the following:

A Na

B Ca

C Mg

D P

View Answer

Answer: Na

17 Some fruits like mango, lemon, raw grapes, orange, etc., have a sour taste due to the presence of:

A Citric acid

B Lactic acid

C Acetic acid

D Oxalic acid

View Answer

Answer: Citric acid

18 Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:

A Remove the layer of magnesium carbonate from the ribbon surface

B Remove the moisture from the ribbon surface

C Make the ribbon surface shinier

D Remove the layer of magnesium oxide from the ribbon surface

View Answer

Answer: Remove the layer of magnesium carbonate from the ribbon surface

19 In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:

A Barium sulphate

B Sulphur

C Hydrochloric acid

D Chlorine

View Answer

Answer: Barium sulphate

20 The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of:

A Physical process

B Endothermic process

C Exothermic process

D Reversible process

View Answer