Chemistry 1998 Jamb Past Questions and Answers

Question 16 :

• JAMB 1998

If an element X of an atomic number Z and mass number Y is irradiated by an intense concentration of neutrons, the relevant nuclear equation is?

A. ^y_zX + ¹₀n → ^{y - 1}_{z + 1}X
B. ^y_zX + ¹₀n → ^{y + 1}_zX
C. ^y_zX + ¹₀n → ^y_{z + 1}X
D. ^y_zX + ¹₀n → ^{y + 1}_{z - 1}X

Question 17 :

• JAMB 1998

90.0g of MgCI₂ was placed in 50.0cm³ of water to give a saturated solubility of the salt is 8.0 mol dm³ at the same temperature, what is the mass of the salt left undissolved at the given temperature?
(Mg = 24, Cl = 35.5)

A. 52.0g
B. 58.5g
C. 85.5g
D. 88.5g

Question 18 :

• JAMB 1998

Soap lather is an example of a colloid in which a?

A. Liquid is dispersed in gas
B. Solid is dispersed in liquid
C. Gas is dispersed in liquid
D. Liquid is despersed in liquid

Question 19 :

• JAMB 1998

The pH of a solution obtained by mixing 100cm³ of a 0.2M solution of NaOH is?

A. 1.3
B. 7.0
C. 9.7
D. 12.7

Question 20 :

• JAMB 1998

Mg²⁺_(aq) + 2e^->_(aq) → Mg_(s)E°_(volts) = 2.370
Zn²⁺_(aq) + 2e^->_(aq) → Zn_(s)E°_(volts) = -0.763
Cds²⁺_(aq) + 2e^->_(aq) → Cd_(s)E°_(volts) = 0.403
Cu²⁺_(aq) + 2e^->_(aq) → Cu_(s)E°_(volts) = 0.340
In the electrochemical series above, the strongest reducing agents is?

A. Cu _(s)
B. Cd_(s)
C. Znsub>(s)
D. Mg_(s)