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Chemistry 2020 WAEC Past Questions

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46

which of the following quantities is a molar quantity?

  • A. Molarity
  • B. Molar mass
  • C. Mass concentration
  • D. Molality
View Answer & Discuss (8) WAEC 2020
47

Dilution factor is the?

  • A. amount of distilled water that is added to the concentrated solution to dilute it
  • B. Quantity of distilled water added to l dm\(^3\) of the concentrated solution to give the dilute solution
  • C. number of times the volume of the concentrated solution is diluted to give the dilute solution
  • D. act of diluting the concentrated solution to obtain the dilute solution
View Answer & Discuss WAEC 2020
48

Calcium chloride is an ionic compound. Which of the following statements account for its ionic character?

I. Calcium has high ionization energy.  II. Calcium has low ionization energy. III. Chlorine has high electron affinity. IV. Chlorine has high Ionization energy.

  • A. I and Il only
  • B. I, II and IV only
  • C. II, IIl and IV only
  • D. I, II, III and IV
View Answer & Discuss (4) WAEC 2020
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49

An example of a biodegradable pollutant is?

  • A. plastic
  • B. sewage
  • C. carbon (II) oxide
  • D. hydrogen sulphide
View Answer & Discuss WAEC 2020
50

(a)(i) State Faraday's first law of electrolysis. (ii) Distinguish between a strong electrolyte and a weak electrolyte

(b) State one chemical property of ethyne.

(c)( i) What is meant by the tern unsaturated hydrocarbon? (ii) Complete the following reaction equation: CH\(_3\) + CH\(_3\)OH-> (iii) Name the major product formed in the cation stated in 1(c)(ii).

(d) State one way by which the rate of esterification could be increased.

(e) Consider the reaction represented by the following equation: Zn + H\(_2\)SO4 → ZnOS\(_4\) + H\(_2\) . If 3.75g of Zn dust was added to excess H\(_2\)SO\(_4\). Calculate the number of molecules of hydrogen gas produced. [ Zn = 65.0, Na = 6.02 X10\(^23\) ].

 (f) State one effect of global warming.

(g) Consider the following reaction equation:

A. Pb(NO\(_3\)) +H\(_2\)S --> PbS + 2HNO\(_3\);

B. H\(_2\) + C\(_2\)H\(_4\) → C\(_2\)H\(_6\).

C. Zn(OH)\(_2\) + 2OH → [ Zn(OH)\(_4\) ]\(^2\).

(i)  Which of the equations represent(s) redox process? (ii) State the change in Oxidation number of the species that are oxidized or reduced. (h)(i) State two of the main concepts of Bohr's model of the atom. (ii) State the limitations of Bohr's model. (i) List three factors that could influence the equilibrium position of a reversible reaction. (j) Calcium trioxocarbonate(iv) powder is added to separate equimolar solutions of hydrochloric acid and ethanoic acid. State one: (i) similarity in the observation in both reactions: (ii) difference in the observation in both reactions.

View Answer & Discuss (3) WAEC 2020
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