Question 161:

• JAMB 1980

In an attempt to remove sugar from a breaker containing a quantity of sand and sugar, 2 M ammonium chloride solution was accidentally added instead of water. Which of the following method could be used to remove the ammonium chloride from the mixture?

A. Fractional distillation
B. Crystallization
C. Filtration followed by evaporation
D. Evaporation followed by sublimation
E. Filtration followed by sublimation

Question 162:

• JAMB 1980

The alloy duralumin is used for the building of aeroplanes because it?

A. Asborbs heat readily from sure thereby preventing the inside of the plane from getting cold at high attitudes
B. Reflects sunlight readily, thereby keeping the inside of the plane cool
C. Is extremely durable and possesses reflective ability
D. Is easily the lightest building material
E. Possesses both strenght and lightness

Question 163:

• JAMB 1980

A solution X on mixing with AgNO₃ solution, gives a white precipitate solution in NH₃. A Solution Y, when added to X, also gives a white precipiate which is soluble on boiling. Solution Y contains?

A. Ag⁺ion
B. Pb²⁺ion
C. Pb⁴⁺ion
D. Zn²⁺ion
E. Al³⁺ion

Question 164:

• JAMB 1980

10cm³ of CO is mixed and sparked with 100cm³ of air containing 21% O₂. If all the volumes measured at S.T.P. the volume of resulting gases would be?

A. 90cm³
B. 100cm³
C. 105cm³
D. 110cm³
E. 115cm³

Question 165:

• JAMB 1980

A sample of an oxide of mercury weighed 1.00g. When this was heated, oxygen was given off, and 1.00g of mercury metal only was left. What is the formula of the oxide?

A. Hg₂O
B. HgO₂
C. HgO₂
D. HgO
E. None of the above