Waec 2014 Chemistry Past Questions And Answers
Which of the following compounds determines the octane rating of petrol?
- A. 1,2,3 - trimethyl pentane
- B. 2,3,5 - trimethyl octane
- C. 2,3,5 - trimethyl pentane
- D. 2,2,4 - trimethyl pentane
The oxide from electric power station is
- A. carbon (IV) oxide
- B. copper (ll) oxide
- C. nitrogen (IV) oxide
- D. sulphur (IV) oxide
Which type of reaction is illustrated by the following equation? C12H26 → 5C2H4+ C2H6
- A. Addition
- B. Cracking
- C. Hydrogenation
- D. Polymerization
The purity of a solid sample can best be determined by its
- A. boiling point
- B. melting point
- C. conductivity
- D. solubility
The electron configuration of26Fe3+ is
- A. [Ar]4s23d6
- B. [AR]4s23d3
- C. [AR]4s13d4
- D. [AR]4s03d5
The enzyme that catalyses the conversion of glucose te ethanol and carbon (IV) oxide is
- A. diastase
- B. maltase
- C. ptyalin
- D. zymase
Hydrogen bonds are formed between molecules containing a hydrogen atom bonded to a
- A. strongly electronegative atom
- B. non-polar species
- C. diatomic element
- D. complex ion
Which of the following organic compounds could be represented by the empirical formula CH2O?
- A. Ethanal
- B. Ethane
- C. Ethanol
- D. Ethanoic acid
Which of the following salts on hydrolysis would give an alkaline solution?
- A. NH4CI(s)
- B. AICI3(s)
- C. CH3COONa(s)
- D. NH4NO3(s)
(a)(i) Define ionic bond.
(ii) What type of bond (s) exist (s) in: I. magnesium oxide; II. ammonium ion?
(b) Determine the oxidation number of sulphur in Na\(_2\)S\(_2\)O\(_2\).
(c) State Faraday's first law.
(d) Give one example each of: (i) acid salt; (ii) base salt.
(e) Name the type of energy change that occurs in each of the following processes
(i) I\(_{2(s)}\) \(\to\) I\(_{2(g)}\)
(ii) Cl\(_{(g)}\) + e\(^{-}\) \(\to\) Cl\(^{-_(g)}\)
(f) State the effect of each of the following aqueous solutions on litmus paper: (i) Na\(_2\)SO\(_{4(aq)}\) (ii) AlCl\(_{3(aq)}\)
(g) Define the term efflorescence.
(h) Give two uses of activated charcoal.
(i) State one use of each of the following processes in the chemical industry: (i) hydrogenation of vegetable oil; (ii) cracking; (iii) esterification.
(j) Calculate the amount of silver deposited in moles when 10920 coulombs of electricity is passed through a solution of a silver salt. [ Faraday constant-- 96500 C mol\(^{-1}\)]