Chemistry Past Questions And Answers
(a) (i) List thetwo gaseous fuels produced from coke.
(ii) Which of thetwo fuels listed in 5(a)(i) is a better fuel?
(iii) Give reasons for your answer in 5(a)(ii)
(iv) Write a balanced equation for the production of each of the fuels. [9 marks]
(b)(i) Differentiate between thermosets and thermoplastics.
(ii) Giveone example of:
I. thermosets;
II. thermoplastics.
(iii) Statethree properties of plastics.
(c)(i) State the method of collecting gases which are denser than air.
(ii) Nametwo gases that could be used to perform the fountain experiment in the laboratory.
(iii) State the physical properties of the gases named in 5(c)(ii) which makes them suitable for the experiment. [4 marks]
(d) (i) Statetwo compounds that could be used to test for water.
(ii) Givethree disadvantages of hard water.
View Discussion (0)WAEC 2018 THEORYDissolving some pellets of NaOH in water would result in
- A. a decrease in the free energy of the solution
- B. a decrease in the entropy of the solution
- C. a lowering of the temperature of te solution
- D. an increase in the entropy of the solution
The maximum number of electrons that can accommodated in the shell having the principal quantum number 3 is
- A. 3
- B. 9
- C. 10
- D. 18
(a)(i) What is a functional group?
(ii) State the functional group in each of the following compounds: I. CH\(_3\)CH\(_2\)CH(CH\(_3\))OH; II. CH\(_3\)CH\(_2\)CH\(_2\)COOH.
(b)(i) Complete the following equations:
(ii) Draw the structure(s) of the product(s) formed in (b)(i) above.
(c)(i).Write an equation for the prepzration of butan-2-ol from butene.
(d) (i) Give the reagents required for the following conversions to take place: I. CH\(_2\) = CH\(_2\) to CH\(_3\)CH\(_2\)OH; II. CH\(_3\)CH\(_2\)OH to CH\(_3\)COOH; Ill. CH\(_3\)COOH to CH\(_3\)COOCH\(_2\)CH\(_3\).
(e) Consider the following organic structure; CH\(_3\)OHCHCH = CHCOOH
(i) State what would be observed when the organic compound is treated with each of the following reagents: I. cold NaHCO\(_{3(aq)}\); II. hot solution of I\(_2\) in NaOH\(_{(aq)}\); Ill. bromine water.
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Calcium tetraoxosulphate (VI) dissolves in water only sparingly to form a
- A. solution
- B. suspension
- C. precipitate
- D. colloid
The number of isomers formed by C6H14 is
- A. 4
- B. 5
- C. 2
- D. 3
The spontaneity of a chemical reaction is determined by the change in the
- A. concentration of the reactants
- B. temperature of the system
- C. free energy of the system
- D. pressure applied to the system
a. Describe how iron and aluminum reacts with each of the following substances: i. dilute \(H_2SO_4\); ii. dilute \(HNO_3\)
bi. Write an equation for the burning of sulphur in air.
ii. Name the catalyst used in the contact process.
iii. In the contact process, why is an excess of air used?
iv. Why is it necessary to cool the catalyst used in 5(b)(ii)?
v. Give a reason why the air used in the contact process needs to be as clean as possible.
vi. State two reasons why SO2 should not be discharged into the atmosphere.
ci. State the reagents and conditions used in the laboratory preparation of chlorine.
ii. State two uses of chlorine.
di. Name the drying agents for each of the following gases: 1. Hydrogen;
i2. sulphur (IV) oxide;
i3. Ammonia.
ii1. State the components of the following
Bronze; ii2. Brass.
View Discussion (0)WAEC 2023 THEORYGiven the half-redox reaction O\(_2\) + 4H\(^+\) + 4e\(^-\) \(\rightarrow\) \(2H_2O\), how many moles of electron will be required produce 3.0 × 1022 molecules of water?
- A) 0.05
- B) 0.10
- C) 0.15
- D) 0.20
Which of the following is not an acid anhydride?
- A. P2O5
- B. NO2
- C. SO2
- D. CO