Urgent WAEC Chemistry Objective Questions for 2023/2024

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February 3, 2023

Urgent WAEC Chemistry Objective Questions for 2023/2024

Urgent WAEC Chemistry Objective Questions for 2023/2024 – here, You can also learn more about expected questions by checking on the previous ones.

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Professionalmarks.com offers you information about WAEC, NECO, GCE, and NABTEB. Detailed past exams questions and answers for this current year.

Urgent WAEC Chemistry Objective Questions for 2023/2024

PAPER 1 (Objectives)

Answer All questions in this section.
Write your answers on the answer sheet provided.

Two immiscible liquids with different boiling points can be separated by _
A. The use of separating funnel
B. Evaporation
C. Distillation
D. Decantation.
A mixture of CaCl2 and CaCO3 in water can be separated by __
A. Evaporation
B. Sublimation
C. Distillation
D. Decantation.
What is responsible for metallic bonding?
A. sharing of electrons between the metal atoms
B. attraction between the atomic nuclei and the cloud of electrons
C. Transfer of electrons from one atom to another
D. attraction between positive and negative ions.
25cm3 of 1.5M solution of NaCl are added to 50cm3 of 3M NaCl. The molar concentration of the resulting solution is __
A. 2.5M B. 3M C. 2.25M D. 4.5M
A solution of salt formed from HCl and NH3 solutions is _
A. Acidic B. Basic C. complex D. Neutral

Urgent WAEC Chemistry Objective Questions for 2023/2024

6. Which of the following elements will burn in excess oxygen to form a product that is neutral to litmus? A. carbon B. Hydrogen C. Sulphur D. Sodium

7. A current was passed for 10 mins and 0.2mole of Cu was deposited. How many grammes of Ag will it deposit?
(Cu = 64, Ag = 108)
A. 43.2g B. 21.6g C. 10.8g D. 5.4g

8. Pollution of underground water by metal ions is very likely in a soil that has high __
A. Acidity B. Alkalinity C. Chloride content D. Nitrate content

9. Producer gas is a gas with low caloric value because it contains more __
A. CO2 than O2 B. N2 than CO C. CO2 than N2 D. N2 than CO2

10. Silver chloride turns grey when exposed to sunlight because _
A. The silver ion is reduced to silver
B. The silver ion is oxidized to silver
C. Silver is a transition metal
D. The silver chloride forms complexes in the sun.

11. Which of these compounds exhibits resonance?
A. Benzene B. Ethanol C. Propene D. Butyne

Urgent WAEC Chemistry Objective Questions for 2023/2024

12. Hydrolysis of CH3COOCH2CH3 in dilute HCl produces __
A. CH3COOH + CH3CH3
B. CH3CH2OH + CH3COCl
C. CH3COOH + CH3CH2OH
D. CH3COOH + CH3CH3

13. Calculate the volume of CO2 measured at s.t.p produced on heating 250g of potassium hydrogen trioxocarbonate (IV) strongly.
(K = 39, H = 1, C = 12, O = 16)
A. 28dm3 B. 2.8dm3 C.5.6dm3 D. 11.2dm3

14. The boiling points of water, ethanol, methylbenzene and butan-2-ol are 373.0K, 351.3K, 383.6K and 372.5K respectively. Which liquid has the highest vapour pressure at 323.0K?
A. Water B. Methylbenzene C. Ethanol D. Butan-2-ol

15. The conclusion from Rutherford’s alpha scattering experiment is that __
A. Atoms are mostly empty space with a small nucleus
B. Emissions from radioactive substances consist of three main components
C. There is a nuclear pull on orbital electrons
D. Electrons are deflected by both magnetic and electric fields.

Urgent WAEC Chemistry Objective Questions for 2023/2024

16. Elements P, Q and R have atomic numbers 9, 16 and 20 respectively. Which of them would gain electron(s) during ionic bonding A. Q and R
B. P and R
C. P and Q
D. P, Q and R.

17. Which of the following has the lowest PH?
A. 5cm3 of M/10 HCl
B. 10cm3 of M/10 HCl
C. 20cm3 of M/8 HCl
D. 15cm3 of M/2 HCl

18. Which of the following is an acid salt?
A. (NH4)2CO3 B. CHCOONa C. KHSO4 D. MgSO4.7H2O

19. Cr2O2-7 + 14H+ + 6I → 2Cr3+ + 3I2 + 7H2O. The change in the oxidation number of oxygen in the equation above is _
A. 0 B. 1 C. 2 D. 7

20. During electrolysis of CuSO4 solution using platinum electrodes, which of the following occurs __
A. Acidity increases at the cathode
B. Oxygen is liberated at the cathode
C. PH decreases at the cathode
D. PH of solution increases.

21. Which of the following ions is a pollutant in drinking water even in trace quantities?
A. Ca2+ B. Pb2+ C. Mg2+ D. Fe2+

Urgent WAEC Chemistry Objective Questions for 2023/2024

22. The solubility of a salt of molar mass 100g at 20oC is 0.34mol/dm3. If 3.4g of that salt dissolved completely 250cm3 of water at that temperature, the resulting solution is __
A. A suspension
B. Saturated
C. Unsaturated
D. Supersaturated

23. Catalyst is important in in chemical industry in that __
A. it affects the purity of the products
B. it affects the quantity of the products
C. it increases the time for reaching equilibrium
D. Bond breaking is slowed down.

24. An alkanioc acid has a molecular mass of 88. Name the acid.
(C = 12, O =16, H = 1)
A. Propanioc acid
B. Botanioc acid
C. Pentanioc acid
D. But-2-ionic acid

25. Ethyne undergoes the following reactions EXCEPT
A. Polymerization B. Addition C. Combustion D. Etherification

SECTION B

1. Compound A consists of carbon and hydrogen only. The compound was found to contain 80% carbon by mass.

(a) Calculate the empirical formula of compound A using the data above.

(b) The relative molecular mass of compound A was found to be 30.

Use this information to deduce the molecular formula of compound A.

[H = 1.00 C = 12.00]

Urgent WAEC Chemistry Objective Questions for 2023/2024

2. (a)When calcium oxide and coke are heated in an electric furnace, the products are carbon (ii) oxide and calcium carbide (CaC2), write the equation for this reaction.

(b)The addition of water to calcium carbide leads to the formation of calcium hydroxide and ethyne. Write the equation for the production of ethyne.

3. Calculate the percentage by mass of silicon tetrachloride.

4. Ammonia, NH3, and phosphine, Ph3, are the hydrides of the first two elements in group 5.

(a)Draw a dot and cross diagram for the ammonia molecule. [2 marks] (b) Sketch and explain the shape of the ammonia molecule.

5. The first ionization energy of chlorine is +1260KJmol-1.

(a)Define the term first ionization energy.

(b)State and explain the general trend in the values of the first ionization energy for the elements across the period, sodium to argon in the periodic table.

6. An aqueous solution has a pH of 4.0.

(a)(i) What is the hydrogen ion concentration of the solution?

(ii)What effect will it have on litmus paper?

(iii)Which of the following salt solutions would have the same effect on litmus? Give a reason for your answer. NH4Cl(aq); NaCl(aq) ; CH3OON(aq).

(b)(i)Differentiate between a fine chemical and a heavy chemical.

(ii)Name two sources of air pollution.

(iii)Suggest one way of reducing air pollution in cities