DHS Assam Mock Test

DHS Assam MCQ Question 

 1. The father of modern chemistry is— 

(a) Priestley 

(b) Lavoisier 

(c) Dalton 

(d) Mendeleeff

Ans:(b) Lavoisier

2. A pure substance can only be____

(a) compound 

(b) an element 

(c) an elementor a compound

(d) a heterogeneous mixture

Ans:(c) an elementor a compound

3. Which one among the following compounds has same equivalent weight and molecular weight ? 

(a) H2SO4 

(b) CaCl2 

(c) Na SO4 

(d) NaCl 

Ans:(d) NaCl

4. The most abundant metal in earth crust is—

(a) iron 

(b) magnesium

(c) calcium 

(d) aluminium

Ans:(d) aluminium

5. Which one of the following is not an element ? 

(a) diamond 

(b) ozone


(d) graphite 

Ans: (c)silica

6. An alloy is–

(a) a compound 

(b) an allotropic form 

(c) an isomer 

(d) a mixture

Ans:(d) a mixture of

7. Name the scientist who stated that matter can be converted into energy–

(a) Boyle

(b) Lavoisier

(c) Avogadro 

(d) Einstein

Ans: (d) Einstein

8. Sodium carbonate crystals lose water molecules. This property is called–

(a) hygroscopy

(b) deliquescence 

(c) efflorescence 

(d) none of these

Ans: (c) efflorescence

9. The law of constant proportions was enunciated by–

(a) Dalton 

(b) Berthelot

(c) Avogadro 

(d) Proust

Ans:(d) Proust

10. The best standard of atomic mass is— 

(a) carbon -12 

(b) oxygen – 16 

(c) hydrogen – 1.008 

(d) chlorine – 35.5

Ans:(a) carbon -12 

11. 1 amu is equal to—

(a) 1.00758 g 

(b) 1.00758 g 

(c) 1.66 10-24 g 

(d) 6.02 x 10-23 g 

Ans:(c) 1.66 10-24 g 

12. One Carbon Credit is equivalent to —

(a) 10 kg of CO2 

(b) 100 kg of CO2 

(c) 1000 kg of CO2 

(d) 10000 kg of CO2

Ans:(c) 1000 kg of CO2

 13. The product of equivalent weight and valency of an

element is equal to—

(a) Vapour density 

(b) Specific heat 

(c) Atomic weight

(d) Molecular weight

Ans:(c) Atomic weight

14. The number of atoms constituting a molecule is called : 

(a) Atomicity 

(b) Molarity 

(c) Valency 

(d) Normality 

Ans:(a) Atomicity

15. Milk is a-

(a) mixture 

(b) element

(c) metal 

(d) none

Ans:(a) mixture

16. Air is —

(a) compound 

(b) element 


(d) solution


17. Which one is the pure element ? 

(a) glass 

(b) cement


(d) none


18. Which one is the compound in the following? 

(a) mercury 

(b) ozone


(d) air


19. Diamond is–

(a) an element 

(b) a compound 

(c) a mixture 

(d) a liquid

Ans:(a) an element

20. If there is one million Mg2+ ions in MgCl, how many chloride ions are there? 

(a) Ten million 

(b) Half a million 

(c)Two million 

(d) One million 

Ans:(c)Two million 

21. Which one of the following is not a characteristic of a compound ? (a) Composition is variable.

(b) All particles of compound are of only one type. 

(c) Particles of compound have two or more elements.

(d) Its constituents cannot be separated by simple physical methods.

Ans:(a) Composition is variable.

22. Which of the following is a mixture ? 

(a) distilled water 

(b) gasoline

(c) liquified petroleum gas 

(d) both (b), (c) 

Ans:(d) both (b), (c)

23. Amixture of sand and naphthalene can be separated by— 

(a) Fractional distillation 

(b) Sublimation 

(c) Chromatography 

d) Any of them 

Ans:(b) Sublimation

24. In known elements, the maximum number is of— 

(a) Metals 

(b) non-metals 

(c) metalloids

(d) none of above 

Ans:(a) Metals

25. The most abundant elements is

(a) Silicon 

(b) Calcium

(c) Nitrogen

(d) Oxygen

Ans:(c) Nitrogen

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