Question 436:

• JAMB 1985

Which of the following conduct electricity?

A. Sulfur
B. Graphite
C. Diamond
D. Red phosphorus
E. Yellow phosphorus

Question 437:

• JAMB 1985

An organic compound contains 72% carbon, 12% hydrogen and 16% oxygen by mass. The empirical formula of the compound is

A. C₈H₂₂O₃
B. C₆H₁₀O₃
C. C₁₂H₁₂O
D. C₆H₁₂O
E. C₃H₆O

Question 438:

• JAMB 1985

0.499g 0f CuSO₄.xH₂O when heated to constant weight gave a residue of 0.346g. the value of x is? (Cu = 63.5, S = 32.0, O = 16, H = 1)

A. 0.5
B. 2.0
C. 3.0
D. 4.0
E. 5.0

Question 439:

• JAMB 1985

In the experiment, which of the following observations would suggest that a solid sample is a mixture? The

A. Solid can be ground to a fine powder
B. Density of the solid is 2.25gdm^-3
C. Solid begins to melt at 573k but is not completely melted until 648k
D. Solid absorbs moisture from the atmosphere and turns into liquid
E. Solid melts at 300k

Question 440:

• JAMB 1985

Hydrogen diffuses through a porous plug

A. At the same rate as oxygen
B. At a slower rate than oxygen
C. Twice as fast as oxygen
D. Three times as fast as oxygen
E. Four times as fast as oxygen