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 1311:

  

  Choose the correct option from the structure above

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is C .
• Question 1312: An acid and its conjugate base Options:
  A) can neutralise each other to form a salt
  B) differ only by a proton
  C) differ only by the opposite charges they carry
  D) are always neutral substances
  Show Answer
  The correct answer is B .
• Question 1313:

  

  Use the solubility curves below to answer questions. If 1 dm³ of a saturated solution of L at 60⁰C is cooled to 25⁰C, what amount in mole will separate out?

  Options:
  A) 0.75
  B) 0.25
  C) 1.00
  D) 0.50
  Show Answer
  The correct answer is A .
• Question 1314:

  What is the mass percentage of carbon (C) in methane (CH4)? (The molar mass of carbon is approximately 12 g/mol.)

  Options:
  A) 25%
  B) 12%
  C) 75%
  D) 50%
  Show Answer
  The correct answer is C .
• Question 1315: CH₃CH₂Cl + KCN → CH₃CH₂CN + KClIn the reaction above, the cyanide is Options:
  A) hydrophobic
  B) hydrophilic
  C) nucleophilic
  D) electrophilic
  Show Answer
  The correct answer is C .
• Question 1316:

  

  The curve depicts titration between

  Options:
  A) Strong acid and strong base
  B) Strong acid and weak base
  C) Weak acid and weak base
  D) Weak acid and strong base
  Show Answer
  The correct answer is C .
• Question 1317:

  Na₂CO₃ + 2HCI → 2NaCI + H₂O + CO₂. Using the above equation, what volume of carbondioxide, measured at s.t.p is liberated when 53g of sodium carbonate is dissolved in hydrochloric acid?

  (1 mole of gas occupies 22.4 dm³ at s.t.p)

  (Na = 23, C = 12, O = 16)

  Options:
  A) 44.8 dm³
  B) 11.2 dm³
  C) 100.1 dm³
  D) 3.0 dm³
  E) 22.4 dm³
  Show Answer
  The correct answer is B .
• Question 1318: When ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is called Options:
  A) ionic bond
  B) electrovalent bond
  C) covalent bond
  D) co-ordinate bond
  E) hydrogen bond
  Show Answer
  The correct answer is D .
• Question 1319: Three drops of a 1.0 mol dm^-3 solution of HCl was added to 20 cm³ of a solution of pH6.4. The pH of the resulting solution will be Options:
  A) close to that of pure water
  B) less than 6.4
  C) greater than 6.4
  D) unaltered
  Show Answer
  The correct answer is B .
• Question 1320: Bronze is an alloy of? Options:
  A) silver and copper
  B) silver and gold
  C) copper and nickle
  D) copper and zinc
  E) copper and tin
  Show Answer
  The correct answer is E .