Enlighten Knowledge Exam; Chemistry MCQS (set 4)

QUESTIONS

1. 3NH₃ is

A. Three moles of Ammonium

B. Six moles of Ammonium

C. Three moles of Ammonia

D. Six moles of Ammonia

2. The following are physical changes except

A. Melting of candle wax

B. Freezing of water

C. Rotting of leaves

D. Dissolving of common salt in water

3. The abnormally high boiling point of water is due to _______

A. Its higher molecular mass

B. The presence of metallic bond

C. The presence of hydrogen bond

D. The presence of a covalent bond

4. What is the IUPAC name for NO₂⁻?

A. Dioxonitrate (IV) ion

B. Trioxonitrate (III) ion

C. Trioxonitrate (IV) ion

D. Dioxonitrate (III) ion

5. The addition of water to calcium oxide leads to _______

A. Chemical change

B. Physical change

C. Combustion change

D. Exothermic change

6. The addition of water to calcium oxide leads to _______

A. Chemical change

B. Physical change

C. Combustion change

D. Exothermic change

7. The formula of sodium troxonitrate (V) is

A. Na₂NO₃

B. S₂NO₃

C. NaNO₃

D. SNO₃

8. Calculate the number of moles in 6.2g of phosphorus [ Given that P=31].

A. 0.40 mole

B. 0.03 mole

C. 0.02 mole

D. 0.20 mole

9. Which of the following methods can be used to separate a mixture of two miscible liquids with different boiling points?

A. Distillation

B. Filtration

C. Evaporation

D. Decantation

10. An element x has isotopic masses of 6 and 7. If the relative abundance is 1:15 respectively, what is the relative atomic mass of x?

A. 7.0

B. 6.1

C. 6.0

D. 6.9

11. Which of the following pairs of species contain the same number of electrons (6C, 8O, 10Ne, 11Na, 12Mg, 13Al, 17Cl)?

A. Cl^– and Ne

B. Mg²⁺ and Al³⁺

C. C and O^2-

D. Na⁺ and Mg

12. Which of the following is not a product of the application of chemistry?

A. Plastic

B. Air

C. Soap

D. Paint

13. Consider the reaction represented by the equation below XNH₃(g) + yCl₂(g)→ ZHCl(g)+N₂(g). The values of x, y, and z are respectively

A. 2,3,6

B. 3,2,6

C. 3,2,4

D. 2,4,6

14. Chlorophyll obtained from green leaves of plants can be shown to be composed of more than one colored component by the technique of ____

A. Chromatography

B. Sublimation

C. Hydrolysis

D. Crystallization

15. The Atomicity of O₃ is

A. 3

B. 1

C. 2

D. 4

16. Which of the following terms indicates the number of bonds that can be formed by an atom?

A. Electronegativity

B. Atomic number

C. Valency

D. Oxidation number

17. Which of the following is not a physical property of matter?

A. Taste

B. Combustion

C. Density

D. Colour

18. These are adverse effects of chemistry except

A. Pollution

B. Population

C. Drug Abuse

D. Corrosion

19. The experiment that showed that atoms have tiny positively charged nucleus was first carried out by

A. Rutherford

B. Millikan

C. Dalton

D. Moseley

20. A molecule is the smallest particle of

A. A lattice that can exist in a free state

B. A radical that can exist in a free state

C. An element that can exist in a free state

D. A matter that can exist in a free state

21. Which of the following apparatuses can be used to measure accurately a specific volume of a liquid?

A. Pipette

B. Beaker

C. Conical flask

D. Measuring cylinder

22. The bonds joining atoms of copper to those of tin in bronze is _____

A. Electrovalent only

B. Electrovalent and Metallic

C. Covalent and Metallic

D. Metallic only

23. Which of the following is a physical change?

A. Exposing white phosphorus to air

B. Burning of kerosene

C. Freezing of ice cream

D. Dissolving calcium in water

24. What is the Oxidation number of sulphur in SO₂?

A. +5

B. +4

C. +3

D. +2

25. Which of the following scientists discovered the electron?

A. Joseph J. Thompson

B. James Chadwick

C. Amedeo Avogadro

D. Ernest Rutherford

26. A coordinate covalent bond could be formed between

A. NH₃ and PCl₃

B. BCl₃ and AlCl₃

C. BCl₃ and NH₃

D. H⁺ and AlCl₃

27. Electrovalent compounds normally

A. have low boiling points

B. have high mobile electrons

C. conduct electricity in solid state

D.  dissolve in polar solvents

28. Which of the following statements about elements in group VII is correct?

A. Br₂ will oxidize Cl^–

B. F₂ has the least tendency to be reduced

C. Cl₂ will oxidize I^–

D. I₂ is a stronger oxidizing agent than F₂

29. Which of the following pairs of molecules form a hydrogen bond?

A. C₂H₅OH and CH₃OH

B. CH₃OH and H₂

C. H₂S and CH₄

D. NH₃ and SO₂

30. Protons and electrons are fundamental particles because they

A. are invisible

B. have different charges

C. are the lightest particles

D. are found in all matter

31. The region around the nucleus where electrons can be located is called

A. spectra

B. an orbital

C. a quanta

D. a field

32. The following ions have the same electron configuration except ₈O, ₁₂Mg, ₁₃Al, ₁₇Cl.

A. Cl^–

B. O^2-

C. Mg²⁺

D. Al³⁺

33. An element, Q, contains 69% of ⁶³Q and 31% of ⁶⁵Q. What is the relative atomic mass of Q?

A. 63.0

B. 63.6

C. 65.0

D. 69.0

34. Potassium trioxonitrate (V) can be obtained from its solution by

A. Distillation

B. Evaporation

C. Crystallization

D. Filtration

35. Which of the following statements about group VII elements is correct?

A. They are present in the same physical state

B. They are a strong reducing agent

C. Their reactivity decreases down the group

D. They exist as monoatomic molecule

36. Elements with high ionization energy would

A. lose electrons easily

B. have large atomic radii

C. have effective nuclear charges

D. has a low atomic number

37. The collision between ideal gas molecules is considered to be perfectly elastic because

A. they collide without losing energy

B. they move randomly in a straight line

C. the average kinetic energy is variable

D. the distance between them is large compared to their sizes

38. Under which conditions of pressure (P) and temperature (T) would the volume of an inflated balloon increase? When

A. both T and P are increased

B. both T and P are decreased

C. T is increased and P is decreased

D. T is decreased and P is increased

39. A molecule of phosphorus is

A. diatomic

B. triatomic

C. tetra atomic

D. monoatomic

40. The most common method of preparing insoluble salt is by

A. filtration

B. decomposition

C. neutralization

D. double decomposition

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Chemistry Questions (Set 3)…

Chemistry trial (Set 2)

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ANSWERS

1. C. Three moles of Ammonia
2. C. Rotting of leaves
3. C. The presence of hydrogen bond
4. D. Dioxonitrate (III) ion
5. A. Chemical change
6. A. Chemical change
7. C. NaNO₃
8. D. 0.20 mole
9. A. Distillation
10. D. 6.9
11. B. Mg²⁺ and Al³⁺
12. B. Air
13. A. 2,3,6
14. A. Chromatography
15. A. 3
16. D. Oxidation number
17. B. Combustion
18. B. Population
19. A. Rutherford
20. D. A matter that can exist in a free state
21. A. Pipette
22. D. Metallic only
23. C. Freezing of ice cream
24. B. +4
25. A. Joseph J. Thompson
26. D. H⁺ and AlCl₃
27. D. dissolves in polar solvents
28. D. I₂ is a stronger oxidizing agent than F₂
29. A. C₂H₅OH and CH₃OH
30. D. are found in all matter
31. B. an orbital
32. A.  Cl^–
33. B. 63.6
34. C. Crystallization
35. C. Their reactivity decreases down the group
36. C. have effective nuclear charges
37. A. They collide without losing energy
38. C.  T is increased and P is decreased
39. C. tetra atomic
40. D. Double decomposition

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