Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 301: Catalytic hydrogenation of benzene produces Options:
  A) Oil
  B) Cyclohexene
  C) Cyclohexane
  D) Margarine
  Show Answer
  The correct answer is C .
• Question 302:

  

  Use the options above to answer this question. Which is the structural formula for pent-2-enoic acid?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is C .
• Question 303: Which of the following metals burns with brick red Options:
  A) Pb
  B) Ca
  C) Na
  D) Mg
  Show Answer
  The correct answer is B .
• Question 304:

  How many grams of methylacetylene (propyne) CH₃ - C Ξ CH will completely discharge the colour of 8g of bromine?

  (Br = 80, C = 12, H = 1)

  Options:
  A) 0.5
  B) 1.0
  C) 2.0
  D) 3.0
  E) 4.0
  Show Answer
  The correct answer is B .
• Question 305: In which of the following reactions can the oxidation number of the nitrogen be said to have increased? Options:
  A) 2NO_(g) + O_2(g) → 2NO_2(g)
  B) NO_(g) + Cl_2(g) → NOCl_2(l)
  C) FeSO_4(aq) + NO_(g) → Fe(NO)SO_4(s)
  D) NO_(g) + Br_2(l) → NOBr_2(l)
  Show Answer
  The correct answer is A .
• Question 306: One method of driving the position of equilibrium of an endothermic reaction forward is to? Options:
  A) increase temperature at constant pressure
  B) dcrease pressure at constant temperature
  C) cool down the apparatus with water
  D) decreases temperature at constant pressure
  Show Answer
  The correct answer is A .
• Question 307:

  A given volume of methane diffuses in 20s. How long will it take the same volume of sulphur (IV) oxide to diffuse under the same conditions?

  [C = 12, H = 1, S = 32, O = 16].

  Options:
  A) 5s
  B) 20s
  C) 40s
  D) 60s
  Show Answer
  The correct answer is C .
• Question 308: A reaction takes places spontaneously if?
  Options:
  A) ∆G = O
  B) ∆S < O and ∆H > O
  C) ∆H < T ∆S
  D) ∆G > O
  Show Answer
  The correct answer is C .
• Question 309: The formula CH₂ for ethanoic acid is regarded as its Options:
  A) Molecular formula
  B) General formula
  C) Empirical formula
  D) Structural formula
  Show Answer
  The correct answer is C .
• Question 310: The radioactive emission with the least ionization power is Options:
  A) $\alpha -particles$
  B) X-rays
  C) $\gamma -rays$
  D) $\beta -rays$
  Show Answer
  The correct answer is C .