Chemistry 1990 Jamb Past Questions and Answers

Question 31 :

• JAMB 1990

Which of the following terms indicates the number of bonds that can be formed by an atom?

A. Oxidation number
B. Valence
C. Atomic number
D. Electronegativity

Question 32 :

• JAMB 1990

X(g) → X\(^-\)(g). The type of energy involved in the above transformation is?

A. Ionization energy
B. Sublimation energy
C. Lattice energy
D. Electron affinity

Question 33 :

• JAMB 1990

Chlorine, consisting of two isotopes of mass numbers 35 and 37, has an atomic mass of 35.5.
The relative abundance of the isotope of mass number 37 is?

A. 20
B. 25
C. 50
D. 75

Question 34 :

• JAMB 1990

10.0 dm³ of air containing H₂S as an impurity was passed through a solution of Pb(NO₃)₂ until all the H₂S had reacted. The precipitate of PbS was found to weigh 5.02 g. According to the equation:
Pb(NO₃)₂ + H₂S → PbS + 2HNO₃ the percentage by volume of hydrogen sulphide in the air is?
(Pb = 207, S = 32, GMV at s.t.p = 22.4dm³)

A. 50.2
B. 47.0
C. 4.70
D. 0.47

Question 35 :

• JAMB 1990

A blue solid, T, which weighed 5.0g was placed on a table. After 8 hours, the resulting pink solid was found to weigh 5.5g. It can be inferred that substance T?

A. Is deliquescent
B. Is hydroscopic
C. Has some molecules of water of crystallization
D. Is efflorescent