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Tuesday, 16 June 2026
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Chemistry Past Questions and Answers

Topic: Separation of mixtures and purification of chemical substances

Jamb Chemistry Questions - Separation of mixtures and purification of chemical substances

Question 96:
The efficiency of petrol as a fuel in high-compression internal combustion engines improves with an increase in the amount of?
  • A Branched chain alkanes
  • B Straight chain alkanes
  • C Cycloalkanes
  • D Halogenated hydrocarbons
View Answer & Explanation
Question 97:
The most volatile fraction obtained from fractional distillation of crude petroleum contains?
  • A Butane , propane and kerosene
  • B Butane , propane and petrol
  • C Ethane, methane and benzene
  • D Methane, ethane and propane
View Answer & Explanation
Question 98:
The solubility of Na3AsO4(H2O)12 is 38.9g per 100g H2O. What is the mass percentage of Na3AsO4 in the saturated solution?
(As = 75, Na = 23, O = 16, H = 1)
  • A 87.27%
  • B 38.9%
  • C 19.1%
  • D 13.7%
View Answer & Explanation
Question 99:
In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity?
  • A Ethanoic acid, milk or magnesia, sodium chloride, hydrochloric acid and sodium hydroxide
  • B Ethanoic acid, hydrochloric acid, milk of magnesia, sodium chloride and sodium chloride and sodium hydroxide
  • C Hydrochloride acid, ethanol acid, sodium chloride, milk of magnesia and sodium hydroxide
  • D Hydrochloride acid, sodium hydroxide sodium chloride, ethanol acid, and milk of magnesia
View Answer & Explanation
Question 100:
If 24.83 cm3 of 0.15 M NaOH is titrated to its end point with 39.45 cm3
of HCl, what is the molarity of the HCl?
  • A 0.094 M
  • B 0.150 M
  • C 0.940 M
  • D 1.500 M
View Answer & Explanation