Chemistry explores the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances. This subject is popular among science students.
Study the following Chemistry past questions and answers for JAMB, WAEC, NECO and Post UTME. Prepare yourself with official past questions and answers for your upcoming examinations.
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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
Exam Body: West African Examinations Council (WAEC)
Explanation provided by Mofiyinfoluwa Ololade
The bond formed between \(\text{H}_2\text{O}\) and \(\text{H}^+\) to form the hydroxonium \(\text{H}_3\text{O}^+\) is
A) Dative
B) Covalent
C) Electrovalent
D) Ionic
Exam Body: West African Examinations Council (WAEC)
An element \(\text{X}\) forms the following oxides \(\text{X}_2\text{O}, \text{XO}\) and \(\text{XO}_2.\) This phenomenon illustrates the law of ________.
A) Conservation of mass
B) Definite proportion
C) Mass action
D) Multiple proportion
Exam Body: West African Examinations Council (WAEC)
How many moles of oxygen would contain \(1.204 \times 10^{24}\) molecules?
NB: Avogadro's constant (NA) \(= 6.02 \times 10^{23}\)
A) 1
B) 2
C) 3
D) 4
Exam Body: West African Examinations Council (WAEC)
\(6.02 \times 10^{23}\) molecules is \(1\) mole
\(1.204 \times 10^{24}\) molecules will be:
\(\cfrac{1.204 \times 10^24 \times 1}{6.02 \times 10^23}\)
\(\cfrac{1.204 \times 10}{6.02}\) \(= \cfrac{12.04}{6.02} = 2\) moles
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
Exam Body: West African Examinations Council (WAEC)
Which of the following apparatus can be used to measure a specific volume of a liquid accurately?
A) Beaker
B) Conical flask
C) Measuring cyclinder
D) Pipette
Exam Body: West African Examinations Council (WAEC)
The general gas equation \(\frac{\text{PV}}{\text{T}} = \text{K}\) 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
Exam Body: West African Examinations Council (WAEC)
The spreading of the scent of a flower in a garden is an example of ________.
A) Brownian motion
B) Diffusion
C) Osmosis
D) Tynadal effect
Exam Body: West African Examinations Council (WAEC)
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
Exam Body: West African Examinations Council (WAEC)
The energy which accompanies the addition of an electron to an isolated gaseous atom is
A) Atomization
B) Electronegativity
C) Electron affinity
D) Ionization
Exam Body: West African Examinations Council (WAEC)