WAEC Chemistry Past Questions and Answers
The West African Examinations Council (WAEC) is a regional examination body responsible for conducting national examinations for secondary school students in West Africa. One of the subjects that WAEC offers is Chemistry.
If you are a student who is preparing for the WAEC Chemistry exam, then you need to be familiar with the past questions.
The past questions can give you an idea of the type of questions that you will be asked on the exam, and they can also help you to identify your weak areas.
In this blog article, I will provide you with a comprehensive guide to WAEC Chemistry past questions and answers.
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How to find WAEC Chemistry past questions
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How to use WAEC Chemistry past questions to prepare for the exam
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FAQ about WAEC Chemistry on Google
How to Find WAEC Chemistry Past Questions
There are a few different ways to find WAEC Chemistry past questions. One way is to purchase a past questions book from a bookstore. Another way is to download the past questions from the WAEC website.
The WAEC website has a section where you can download past questions for all of the subjects that WAEC offers. The past questions are available in PDF format.
WAEC Chemistry Past Questions PAPER 2 (ESSAY)
SECTION A
1. Compound A consisting 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]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. [2 marks]
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. [3 marks]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
WAEC Chemistry Past Questions SAMPLE QUESTIONS PAPER 1 (OBJECTIVE TEST)
1. Isotopes of the same element have the same number of
A. Protons, neutrons, and electrons.
B. Protons and neutrons but a different number of electrons.
C. Protons and electrons but different number of neutrons.
D. Neutrons and electrons but a different number of protons.2. Which type of chemical bond is formed by the transfer of electrons?
A. Covalent
B. Dative
C. Ionic
D. Metallic3. The concentration of an aqueous solution is 5mg dm-3. Determine is the concentration in parts per million (ppm).
A. 500 ppm
B. 50 ppm
C. 10 ppm
D. 5 ppm4. Consider the following species: H, H+, H-. What is the number of electrons in each of the species respectively?
A. 1, 0, 2
B. 0, 1, 2
C. 2, 1, 0
D. 1, 2, 05. Two electrons can occupy the same orbital if they have different
A. Angular momentum quantum numbers.
B. Magnetic quantum numbers.
C. Principal quantum numbers.
D. Spin quantum numbers.6. What mass of NaOH is required to make 250 cm3 of 0.10mol/dm-3 solution? [Na = 23, O = 16, H = 1]
A. 1 g
B. 4 g
C. 8 g
D. 16 g7. Which of the following substances is not a hydrocarbon?
A. Benzene
B. Butane
C. Ethyne
D. Ethanamide8. A substance which ionizes completely into hydroxonium ions is a
A. Strong acid.
B. Strong base.
C. Weak acid.
D. Weak base.9. Which of the following solutions is able to resist changes in pH when small amounts of an acid or a base is added?
A. Buffer solution
B. Neutral solution
C. Saturated solution
D. Supersaturated solution10. Protein is a polymer formed from the linkage of
A. Amino acid molecules.
B. Fatty acid molecules.
C. Glucose units.
D. Monosaccharides.
11. The bond formed between H2O and H+ to form the hydroxonium H3O+ is
A) Dative
B) Covalent
C) Electrovalent
D) Ionic
12. The minimum amount of energy required for effective collisions between reacting particles is known as
A) Activation energy
B) Bond energy
C) Kinetic energy
D) Potential energy
13. An element X forms the following oxides X2O,XO and XO2.This phenomenon illustrates the law of ________
A) Conservation of mass
B) Definite proportion
C) Mass action
D) Multiple proportions
14. How many moles of oxygen would contain 1.204×1024 molecules?
NB: Avogadro’s constant (NA) =6.02×1023
A) 1
B) 2
C) 3
D) 4
15. Which of the following statements about solids is correct?
A) Solid particles are less orderly than those of a liquid
B) Solid have lower densities than liquids
C) Solid particles have greater kinetic energies than those of liquids
D) Solid particles cannot be easily compressed
16. Which of the following apparatus can be used to measure a specific volume of a liquid accurately?
A) Beaker
B) Conical flask
C) Measuring cylinder
D) Pipette
17. The general gas equation PVT=K is a combination of
A) Boyle’s and Charles’ laws
B) Boyle’s and Graham’s laws
C) Charles’ and Graham’s laws
D) Dalton’s and Graham’s laws
18. The spreading of the scent of a flower in a garden is an example of ______
A) Brownian motion
B) Diffusion
C) Osmosis
D) Tyndal effect
19. Propane and carbon (IV) oxide diffuse at the same rate because [H = 1.00, C = 12.0, O = 16.0]
A) They are both gases
B) Their molecules contain carbon
C) They have the same relative molecular mass
D) Both are denser than air
20. The energy which accompanies the addition of an electron to an isolated gaseous atom is
A) Atomization
B) Electronegativity
C) Electron affinity
D) Ionization
FAQ
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What are the benefits of using WAEC Chemistry past questions?
There are many benefits to using WAEC Chemistry past questions. First, they can help you to get familiar with the format of the exam. Second, they can help you to identify your weak areas. Third, they can help you to practice answering questions under timed conditions.
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Where can I find WAEC Chemistry past questions?
There are a few different places where you can find WAEC Chemistry past questions. You can purchase them from a bookstore, download them from the WAEC website, or find them online.
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How do I use WAEC Chemistry past questions to prepare for the exam?
The best way to use WAEC Chemistry past questions to prepare for the exam is to start by reading through them. This will give you an idea of the type of questions that you will be asked on the exam. Once you have read through the past questions, you can start practicing answering them. You can do this by yourself or with a friend.
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What are the different question types on the WAEC Chemistry exam?
The WAEC Chemistry exam includes a variety of question types, such as multiple choice, fill in the blank, and essay questions. It is important to be familiar with all of the different question types so that you can answer them confidently on the exam.
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What is the best way to study for the WAEC Chemistry exam?
The best way to study for the WAEC Chemistry exam is to create a study plan and stick to it.
