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 891: What volume of CO₂ at s.t.p would be obtained by reacting trioxocarbonate (IV) with excess acid?(G.M.V at s.t.p = 22.4 dm³) Options:
  A) 2.240 cm ³
  B) 22.40 cm ³
  C) 224.0 cm ³
  D) 2240 cm ³
  Show Answer
  The correct answer is B .
• Question 892:

  

  Choose the correct answer in the option above.

  Which of the following is a primary amine?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .
• Question 893: A metallic ion X²⁺ with an inert gas structure contains 18 electrons. How many protons are there in this ion? Options:
  A) 20
  B) 18
  C) 16
  D) 2
  Show Answer
  The correct answer is A .
• Question 894:

  Na${}_2$CO${}_3$ + 2HCl $\to$ 2NaCl + H${}_2$O + CO${}_2$

  The indicator most suitable for this reaction should have a pH equal to

  Options:
  A) 5
  B) 7
  C) 3
  D) 9
  Show Answer
  The correct answer is C .
• Question 895:

  1.1 g of CaCI₂ dissolved in 50 cm³ of water caused a rise in temperature of3.4°C. The heat of reaction, ∆H for CaCI₂ in kj per mole is?

  (Ca = 40, CI = 35.5, specific heat of water is 4.18 jk^-1

  Options:
  A) -71.1
  B) -4.18
  C) +71.1
  D) +111.0
  Show Answer
  The correct answer is A .
• Question 896:

  

  It can be deduced from the vapour pressure curves above that

  Options:
  A) liqiud 1 has the highest boiling point
  B) liquid ll has the highest boiling point
  C) liquid lll has the highest boiling point
  D) liquid lll has the lowest boiling point
  Show Answer
  The correct answer is C .
• Question 897:

  On which of the following is the solubility of a gaseous substance dependent? 

  I. Nature of solvent 

  II. Nature of solute 

  III. Temperature 

  IV. Pressure

  Options:
  A) I, II, III and IV
  B) I and II only
  C) II only
  D) I, III and IV only
  Show Answer
  The correct answer is D .
• Question 898: Water is poured over a white solid and a colourless neutral gas is evolved which burns with a sooty flame. The white solid is? Options:
  A) calcium
  B) calcium oxide
  C) calcium carbide
  D) sodium peroxide
  E) sodium sulphate
  Show Answer
  The correct answer is C .
• Question 899: A mixture of petrol and water can be separated through Options:
  A) centrifugation
  B) distillation
  C) the use of separating funnel
  D) the use of filter paper
  Show Answer
  The correct answer is C .
• Question 900:

  2Na ₂ O _2(s) + 2H ₂ O ₂₍₁₎ → 4 NaOH_(s) +O_2(s)

  The substance that is oxidized in the reaction above is

  Options:
  A) 2NaO_2(s)
  B) NaOH(aq)
  C) H₂O₍₁₎
  D) O_2(g)
  Show Answer
  The correct answer is A .