Question 471:

• JAMB 1986

A white solid suspected to be lead trioxonitrate (V) zinc trioxocarbonate (IV) or calcium trioxocabonate (IV) was heated strongly. Its residue which was yellow when hot and white when cold is?

A. Lead (II) oxide
B. Calcium oxide
C. Zinc oxide
D. Lead nitrate

Question 472:

• JAMB 1986

Which of the following compounds would give lilac flame coloration and a white precipitate with acidified barium chloride solution?

A. KCI
B. NaNO₃
C. K₂SO₄
D. CaSO₄

Question 473:

• 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 474:

• 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 475:

• 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