Question 656:

• 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 657:

• 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 658:

• 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 659:

• 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

Question 660:

• JAMB 1990

The solubility in moles per dm³ of 20g of CuSO₄ dissolve in 100 of water at 180°C is?
(Cu = 63.5, S = 32, O = 16)

A. 0.13
B. 0.25
C. 1.25
D. 2.00