Home ยป Past Questions ยป Chemistry ยป Waec ยป 1991 ยป Page 2
22

An organic compound which reacts readily with bromine to form a compound with the formula CH3CHBrCH2Br is

  • A. ethene
  • B. propane
  • C. butane
  • D. propene
  • E. propyne
View Answer & Discuss WAEC 1991
23

When a crystal was added to its solution, it did not dissolve and the solution remained unchanged, showing that the solution was

  • A. concentrated
  • B. supersaturated
  • C. unsaturated
  • D. colloidal
  • E. saturated
View Answer & Discuss WAEC 1991
24

A current of 4.0 amperes was passed through copper (ll) tetraoxosulphate (IV) solution for one hour using copper electrodes. What was the mass of copper deposited? (Cu = 64, 1F = 96500 C)

  • A. 3.2g
  • B. 4.8g
  • C. 6.4g
  • D. 48g
  • E. 96g
View Answer & Discuss WAEC 1991
25

In which of the following crystals are the particles held by van der Waal’s forces only?

  • A. Sodium chloride
  • B. Ice
  • C. Diamond
  • D. Iodine
  • E. Quartz
View Answer & Discuss WAEC 1991
26

Compounds that have the same molecular formula but different structures are said to be

  • A. allotropic
  • B. polymorphic
  • C. polymeric
  • D. isomeric
  • E. isotopic
View Answer & Discuss WAEC 1991
27

Which of the following properties is not characteristic of electrovalent compounds?

  • A. formation of crystalline solids
  • B. solubility in polar solvents
  • C. high vapour pressures
  • D. high melting and boiling points
  • E. ability to conduct electricity in aqueous solution
View Answer & Discuss WAEC 1991
28

How many principal electronic shells has an atom whose electronic configuration is shown below? 1s22s22p63s1

  • A. 1
  • B. 2
  • C. 3
  • D. 4
  • E. 11
View Answer & Discuss WAEC 1991
29

Which of the following is not a direct petroleum product?

  • A. Methane
  • B. Ethanol
  • C. Petrol
  • D. Vaseline
  • E. Kerosene
View Answer & Discuss WAEC 1991
30

Which of the reactions represented by the following equations will take place at room temperature?

  • A. C 6 H2O โ†’ CO + H2
  • B. CuO + H2 โ†’ Cu + H2O
  • C. N2 + 3H2 โ†’ 2NH3
  • D. 2Na + 2H2O โ†’ 2NaOH + H2
  • E. 2Fe + 3CI2 โ†’ 2FeCI3
View Answer & Discuss WAEC 1991
31

When starch undergoes complete enzyme-catalyzed hydrolysis, the resulting product is

  • A. glucose
  • B. maltose
  • C. sucrose
  • D. fructose
  • E. cellulose
View Answer & Discuss WAEC 1991
32

In the redox reaction represented by the following equation: Cu2+aq + Zn(s) โ†’ Cu(s) + Zn2+

  • A. the oxidation number of copper increases
  • B. copper (ll) ions are reduced to copper atoms
  • C. zinc atoms are reduced to zinc ions
  • D. copper (ll) ions donate electrons to zinc atoms
View Answer & Discuss WAEC 1991
33

The ratio of reactants to products is 1: 3: 2 in the reaction represented by the equation below: N2,/SUB> (g) โ†’ 2NH3(g) which of the following law is demonstrated by this?

  • A. Boyle's law
  • B. Law of multiple proportion
  • C. Gay Lussac's law
  • D. Law of constant composition
  • E. Avogadro's law
View Answer & Discuss WAEC 1991
34

Esterification of propane 1,2,3-triol and unsaturated higher carboxylic acids will produce

  • A. fats
  • B. soap
  • C. methly-propanoate
  • D. alkanols
  • E. oils
View Answer & Discuss WAEC 1991
35

2NaNO3 โ†’ 2NaNO2 + O2. From the equation above, what is the volume of oxygen produced at s.t.p. when 8.5g of 2NaNO3 is heated until no further gas is evolved? (2NaNO3 = 85, molar volume of gases at s.t.p. = 22.4dm3)

  • A. 1.12dm3
  • B. 2.24dm3
  • C. 4.48dm3
  • D. 11.2dm3
  • E. 22.4dm3
View Answer & Discuss WAEC 1991
36

Consider the reaction represented by the equation below: H2(g) + 12(s) โ‡Œ 2HI(g) โˆ†H negative. Which of the following takes place when the temperature of the reaction vessel is decreased?

  • A. the gases condense
  • B. the yield of hydrogen increases
  • C. the concentration of the reactants remain constant
  • D. more of the hydrogen iodide decomposes
  • E. the yield of hydrogen iodide increases
View Answer & Discuss WAEC 1991
37

CH4(g) + 2O2(g) โ†’ 2H2O(l) + CO2(g) โˆ†H = 890KJ mo-1 โˆ†H in the reaction represented by the equation above is the enthalpy of

  • A. formation
  • B. combustion
  • C. solution
  • D. activation
  • E. neutralization
View Answer & Discuss WAEC 1991
38

A compound which liberates carbon (IV) oxide from a hydrogentrioxocarbonate (lV) could have the molecular formula

  • A. C2H5OH
  • B. C 3H 4
  • C. HCOOH
  • D. H2O2
  • E. C6H6
View Answer & Discuss WAEC 1991
39

In which of the following are the substances arranged in their correct order of increasing melting point?

  • A. Sodium chloride, sulphur, diamond
  • B. Diamond, sodium chloride, sulphur
  • C. Sulphur, sodium chloride, diamond
  • D. Diamond, sulphur, sodium chloride
  • E. Sulphur, diamond, sodium chloride
View Answer & Discuss WAEC 1991
40

Which of the following statements is not correct? Group 7 elements

  • A. are diatomic
  • B. are good oxidizing agents
  • C. are highly electronegative
  • D. have relatively low ionization potentials
  • E. have high electron affinity
View Answer & Discuss WAEC 1991
41

Which of the following modes of motion is exhibited by the particles of a solid?

  • A. Vibrational and random motion
  • B. Vibrational and translational motion
  • C. Translational and random motion
  • D. Vibrational motion only
  • E. Translational motion only
View Answer & Discuss WAEC 1991
42

The products of the electrolysis of dilute sodium chlorid solution with platinum electrodes are

  • A. hydrogen and oxygen
  • B. oxygen and chlorine
  • C. chlorine and water
  • D. sodium amalgam and chlorine
  • E. sodium hydroxide and water
View Answer & Discuss WAEC 1991