Chemistry 2010 JAMB Past Questions

Chemistry 2010 JAMB Past Questions

1. Which of the following is an example of a mixture?

• A. Common salt
• B. Blood
• C. Sand
• D. Washing soda

Correct Answer: Option B

2. Calculate the percentage by mass of nitrogen in calcium trioxonitrate (V)

[Ca = 40, N = 14, O = 16]

• A. 8.5%
• B. 13.1%
• C. 17.1%
• D. 27.6%

Correct Answer: Option C

 

3. The droplets of water observed around a bottle of milk taken out of the refrigerator is due to the fact that the

• A. water vapour in the air around the bottle gains some energy from the bottle
• B. temperature of the milk drops as it loses heat into the surroundings
• C. saturated vapour pressure of the milk is equal to the atmospheric pressure
• D. water vapour in the air around the bottle loses some of its energy to the bottle

Correct Answer: Option D

4.The volume of a given gas is V cm³ P mm Hg. what is the new volume of the gas if the pressure is reduced to half at constant temperature

• A. 4 V cm³
• B. 2 V cm³
• C. V/2 cm³
• D. V cm³

Correct Answer: Option B

 

5. Moving from left to right across a period, the general rise in the first ionization energy can be attributed to the

• A. decrease in nuclear charge
• B. increase in nuclear charge
• C. decrease in screening effect
• D. increase in screening effect 

Correct Answer: Option B

6. How many unpaired electron(s) are there in the nitrogen sub-levels/

• A. 3
• B. 2
• C. 1
• D. none

Correct Answer: Option A

 

7. The stability of the noble gases is due to the fact that they

• A. have no electron in their outermost shells
• B. have duplet or octet electron configurations
• C. belong to group zero of the periodic table
• D. are volatile in nature

Correct Answer: Option B

8. The maximum number of electrons in the L shell of an atom is

• A. 2
• B. 8
• C. 18
• D. 32

Correct Answer: Option B

9. Elements in the same period in the periodic table have the same

• A. number of shells
• B. atomic number
• C. chemical properties
• D. physical properties

 

Correct Answer: Option A

 

10

₁²D + ₁³T → ₂⁴He + ₀¹n + energy
The reaction above illustrates

• A. alpha decay
• B. artificial transmutation
• C. nuclear fussion
• D. nuclear fission

Correct Answer: Option C

11. A noble gas with a high power of fog penetration used in aerodrome beacons is

• A. krpton
• B. argon
• C. helium
• D. neon

Correct Answer: Option D

12. Permanent hardness of water can be removed by

• A. filtration
• B. adding slaked lime
• C. adding caustic soda
• D. boiling

Correct Answer: Option C

13. Substance employed as drying agents are usually

• A. amphoteric
• B. hydroscopic
• C. efflorescent

Correct Answer: Option B

14. Calculate the solubility in mol dm^-3 of 40g of CuSO₄ dissolved in 100g of water at 120^oC.

[Cu = 64, S = 32, O = 16]

• A. 4.00
• B. 2.50
• C. 0.40
• D. 0.25

Correct Answer: Option B

15. Coffee stains can best be removed by

• A. Kerosine
• B. turpentine
• C. a solution of borax in water
• D. ammonia solution

Correct Answer: Option C

16. Carbon (II) oxide is considered dangerous if inhaled mainly because it

• A. can cause injury to the nervous system
• B. competes with oxygen in the blood
• C. competes with carbon (IV) oxide in the blood
• D. can cause lung cancer

Correct Answer: Option B

17. The acid that is used to remove rust is

• A. boric
• B. hydrochloric
• C. trioxonitrate (V)
• D. tetraoxosulphate (VI)

Correct Answer: Option B

18. Calculate the volume of 0.5 mol dm^-3 H₂So₄ that is neutralized by 25 cm³ of 0.1 mol dm^-3 NaOH

• A. 5.0 cm³
• B. 2.5 cm³
• C. 0.4 cm³
• D. 0.1 cm³

Correct Answer: Option B

 

19. The colour of methyl orange in alkaline medium is

• A. yellow
• B. pink
• C. orange
• D. red

Correct Answer: Option A

Explanation

Methyl orange has the property to color alkaline and neutral water yellow

 

20. Which of the following salts is slightly soluble in water?

• A. AgCl
• B. CaSO₄
• C. Na₂CO₃
• D. PbCl₂
  

  Correct Answer: Option B

  Explanation

  All sulfates are soluble except those of barium, strontium and lead. Calcium sulfate, silver sulfate and mercurous sulfate are slightly soluble in water, but calcium sulfate is rarely precipitated in reactions between the calcium and sulfate ions.
  
  
  

   

  21

  6AgNO_4(aq) + PH_3(g) + 3H₂O_(l) → 6Ag_(s) + H₃PO_3(g) + 6HNO_3(aq)
  In the above reaction, the reducing agent is

  • A. HNO_3(aq)
  • B. H₂O_(l)
  • C. PH_3(g)
  • D. AgNO_3(aq)

  Correct Answer: Option C

  22. The IUPAC nomenclature of the compound LiAlH₄ is

  • A. lithiumtetrahydridoaluminate (III)
  • B. aluminium tetrahydrido lithium
  • C. tetrahydrido lithium aluminate (III)
  • D. lithium aluminium hydride

   

  Correct Answer: Option A

  23. Iron can be protected from corrosion by coating the surface with

  • A. gold
  • B. silver
  • C. copper
  • D. zinc

  Correct Answer: Option D

  24. What quantity of aluminium is deposited when a current of 10A is passed through a solution of an aluminium salt for 1930s?

  [Al = 27, F = 96500 C mol ^-1]

  • A. 0.2 g
  • B. 1.8 g
  • C. 5.4 g
  • D. 14.2 g

  Correct Answer: Option B

   

  25. In which of the following is the entropy change positive?

  • A. Thermal dissociation of ammonium chloride
  • B. Reaction between an acid and a base
  • C. Addition of concentrated acid to water
  • D. Dissolution of sodium metal in water 

  
  

  Correct Answer: Option A