Jamb Chemistry 1986 Past Questions and Answers

Question 26:

• JAMB 1986

How will a metal X, which reacts explosively with air and with dilute acids be best extracted from its ores?

A. Electrolysis of solution of its salts
B. Decomposition of its oxides
C. Displacement from solution by an alkali metal
D. Electroiysis of fused salt

Question 27:

• JAMB 1986

Which of the following is NOT correct test for the named organic compound in each case?

A. Butanoic acid solution gives effervescence with Na₂CO₃ solution
B. Glucose when reacted with Na₂CrO₄ at 0°C will show immediate discharge of colour
C. When but-2-ene is reacted with dilute solution of KMnO₄ the purple colour of KMnO is discharged readily even room temperature
D. When butan-2-ol is boiled with butanoic acid with a drop of concentrated H₂SO₄ a sweet smelling liquid is produced

Question 28:

• JAMB 1986

Which of the following is used as an 'anti-knock' in automobile engines?

A. Tetramethyl silane
B. Lead tetra-ethyl
C. Glycerol
D. N-heptane

Question 29:

• JAMB 1986

What reaction takes place when palm-oil is added to potash and foam are observed?

A. Neutralization
B. Saponification
C. Esterification
D. Salting-out

Question 30:

• JAMB 1986

When ethanol is heated with excess concentrated sulphuric acid, the ethanol is?

A. Oxidized to ethene
B. Polymerized to polyethene
C. Dehydrated to ethene
D. Dehydrated to ethyne