DAY(1) JAMB 2023 CHEMISTRY QUESTIONS FROM EXAMKING.NET

Chemistry

1..An isotope has an atomic number of 15 and mass number of 31..The proton it contain is
A..16
B..15
C..31
D..46

2. Calculate the volume in cm³ of oxygen evolved at s.t.p. when a current of 5A is passed through acidified water for 1..(Molar volume of gas at STP =22.4DM³
A..0.056
B..0.224
C..224.000
D..56.0000

3. The sulphide used in coating electric fluorescent tubes is
A)iron(II) sulphide
B)sphalerite
C)zinc sulphide
D) sulphide mineral

4. Hydrogenation of Benzene to Cyclohexane
A. Cracking
B. Polymerisation
C. Reforming
D. Aromatization

5. If the half life of a particle is 4.5 how long will it decay 3/4 of its mass.

6. BaS04 is
A)soluble salt
B)insoluble salt
C)neutral salt
D)basic sat

7. The gas that can best be collected by downward displacement of air is
A. Ammonia
B. Carbon (iV) oxide
C. Chlorine
D. Sulphur (iV) oxide

8. The pollutant that contributes to the depletion of the ozone layer is

a)CFCs
B)CFs
C)CFS
D)CFC

9. What changes sodium pellets to liquid
a. Oxygen
b. Water vapour
c. Carbon(Iv) oxide
d. Nitrogen

10. The compound used as “antifreeze” in car radiators in cold regions of the world is
A. Ethanol
B. Ethylene glycol
C. Ethanal
D. Propane-1, 2-diol

11. The PH of 0.001dm³ of HCl is ???

12. What are the laws that form the general gas equation
A. Boyle and Charles
B. Boyle’s, Charles and Graham
C. Boyle’s only
D. Charles and Graham

13. Chlorine, bromine, and iodine resembles each other in that all
A. Dissolves in alkalis
B. Displace each other from solution of their salts
C. React violently with hydrogen with heating

14. What changes sodium pellets to liquid
a. Oxygen
b. Water vapour
c. Carbon(Iv) oxide
d. Nitrogen

15. The method suitable for separating suspended particles in liquid is….?
A. Decantation
B. Distillation
C. Centrifugation

16. A hydrocarbon X has molar mass 26 carban Atoms 96% what is it’s molecular formula
A. C2H2
B. C2H6
C. CH4
D. C3H8

17. Silica gel when exposed to air turns liquid what kind of substance is it
A) delinquency
B)hygroscopic
C) efflorescence

18. In an equilibrium reaction, which of the following conditions indicate the maximum yield of the product will be obtained
A. Equilibrium constant is very large
B. ∆H – T∆S
C. ∆H > T∆S
D. Equilibrium constant is less than zero

19. Under high pressure,real gases do not obey gas laws because their molecules?
a.Have become more energetic
b.Have become less energetic
c.Have become smaller in size
d.Decompose into atoms

20. Which of the following has the highest-octane number?
A. Straight chain aliphatic compound
B. Branched chain aliphatic compound
C. Aromatic compound
D. Cyclic aliphatic compound

More coming ✅