Jamb 1993 Chemistry Past Questions And Answers
1
Catalytic hydrogenation of benzene produces?
- A. an aromatic hydrocarbon
- B. margarine
- C. cyclohexane
- D. D.D.T
2
Which of the following represents saponification?
- A. Reaction of carboxylic acids with sodium hydroxide
- B. Reaction of alkanoates with acid
- C. Reaction of alkanoates with alcohols
- D. Reaction of alkanoates with sodium hydroxide
3
Two atoms represented as U and U are?
- A. isomers
- B. allotropes
- C. isotopes
- D. anomers
4
The confirmatory test for alkanoic acids in organic qualitative analysis is the?
- A. turning of wet blue litmus paper red
- B. reaction with alkanols to form esters
- C. reaction with sodium hydroxide to form salt and water
- D. reaction with aqueous Na2COsp3 to liberate a gas which turns lime water milky
5
A balanced chemical equation obeys the law of?
- A. conservation of mass
- B. difinite proportions
- C. multiple proportions
- D. conservation of energy
6
Which of the following is NOT true of metals?
- A. They are good conductors of electricity
- B. They ionize by electron loss
- C. Their oxides are acidic
- D. They have high melting points
7
Bronze is an alloy of?
- A. silver and copper
- B. silver and gold
- C. copper and nickle
- D. copper and tin
8
The phenomenon whereby sodium trioxocarbonate (IV) decahydrate loses some of its water of crystallization on exposure to the atmosphere is known as?
- A. deliquescene
- B. hygroscopy
- C. effervescence
- D. efflorescence
9
A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is?
- A. sulphur (ii) oxide
- B. hydrogen sulphide
- C. sulphide (lV) oxide
- D. hydrogen chloride
10
10g of a solid is in equilibrium with its own vapour. When 1 g of a small amount of solid is added, the vapour pressure?
- A. remains the same
- B. drops
- C. increases by 1%
- D. increases by 99%