Jamb Chemistry 1983 Past Questions and Answers

Question 11:

• JAMB 1983

An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.
Reaction of X with yeast forms the basis of the

A. Plastic industry
B. Textile industry
C. Brewing industry
D. Soap industry
E. Dyeing industry

Question 12:

• JAMB 1983

A mixture of common salt, ammonium chloride and barium sulphate can best be separated by

A. Addition of water followed by filtration then sublimation
B. Addition of water followed by sublimation then filtration
C. Sublimation followed by addition of water then filtration
D. Fractional distillation
E. Fractional crystallization

Question 13:

• JAMB 1983

Which of the following relationships between the pressure P, the volume V and the temperature T, represents an ideal gas behaviour?

A. P \(\alpha\) VT
B. P \(\alpha\) T/V
C. PT \(\alpha\) V
D. PV \(\alpha\) I/T
E. P \(\alpha\) V/T

Question 14:

• JAMB 1983

The colour imparted to a flame by calcuium ion is

A. Green
B. Blue
C. Brick-red
D. Yellow
E. Lilac

Question 15:

• JAMB 1983

In the reaction M + N P;∆H = + QKJ. Which of the following would increase the concentration of the product?

A. Decreaseing the concentration of N
B. Increasing the concentration of P
C. Adding a suitable catalyst
D. Decreasing the temperature
E. Increasing the temperature