Chemistry Past Questions and Answers

Element X has a total of 19 electrons and can react with oxygen to form an oxide. Which of the following statements is NOT true of the oxide of the element?

A When exposed to air, it slowy changes to liquid
B Its solution in water conducts electricity
C Its solution in water, on evaporationm gives a white solid
D Its solution in water liberates hydroge when in contact with aluminium metal
E Its oxide, when stronlgy heated, regenerates the elements X

Question 17:

Which ONE of the following statements is true?

A All alkali metals salts dissolves with dissociation in water
B Most ionic substances are easily vaporized
C Ionic substances exist only as liquid
D Non-ionic substances are good electrolytes
E Nitrogen exists in a trivalent state in ammonium salts

Question 18:

When ethene gas reacts with chlorine gas to form 1, 2-dichloroethene, the reaction is called?

A Substitution
B Addition
C Polymerization
D Hydrolysis
E Reduction

Question 19:

20 cm3 of 1 M H\(_2\)SO\(_4\) is mixed 20 cm\(^3\) of 1 M NaOH. The resulting solution is?

A Acidic with a molarity of 0.50 M H₂SO₄
B Acidic with a molarity of 0.25 H₂SO₄
C Neutral
D Alkaline with a molarity of 0.25 M NaOH
E Alkaline with a molarity of 0.50 M NaOH

Question 20:

Which of the following is acceptable as the organic product of the reaction of ethanoic acid and ethanol with an acid catalyst?

A Ethyl ethanoate
B Methyl ethanoate
C Ethyl methyl ketone
D Butanol
E None