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 1571:

  Stainless steel is an alloy made up of

  Options:
  A) Iron and zinc
  B) Copper and tin
  C) Iron and chromium
  D) Iron and carbon
  Show Answer
  The correct answer is C .
• Question 1572: Methanoic acid mixes with water in all proportions and has about the same boiling point as water which of the following methods would you adopt to obtain pure water from a mixture of stand, water and methanoic acid? Options:
  A) fractional distillation
  B) filtration followed by distillation
  C) neutralization with sodium hydroxide followed by distillation
  D) esterification with ethanol followed by distillation
  E) neutralization with sodium hydroxide followed by filtration
  Show Answer
  The correct answer is B .
• Question 1573:

  What volume of (dm${}^3$) of water will be added to 10dm${}^3$ of 2.0 mol/dm${}^3$ HCL acid solution to give a final solution of 0.5 mol/dm${}^3$?

  Options:
  A) 30
  B) 40
  C) 20
  D) 50
  Show Answer
  The correct answer is B .
• Question 1574: What is the valence shell electron configuration of the element with atomic number 17? Options:
  A) 1s² 2s² 2p⁶ 3s² 3p⁴
  B) 1s² 2s² 2p⁶ 3s² 3p⁵
  C) 2s² 2p⁶
  D) 3s² 3p⁵
  Show Answer
  The correct answer is B .
• Question 1575:

  A given amount of gas occupies 10.0dm5 at 4atm and 273°C. The number of moles of the gas present is [Molar volume of gas at s.t.p = 22.4dm${}^3$]

  Options:
  A) 0.89 mol
  B) 1.90 mol
  C) 3.80 mol
  D) 5.70 mol
  Show Answer
  The correct answer is A .
• Question 1576: Coal gas is made up of carbon (II) oxide, hydrogen and? Options:
  A) nitrogen
  B) air
  C) argon
  D) methane
  Show Answer
  The correct answer is D .
• Question 1577:

  0.16g of methane when burnt raises the temperature of 100g of water by 40°C. What is the of combustion of methane when if the heat capacity of water is 4.2 Jg^-1°C^-1?

  (CH₄ = 16)

  Options:
  A) 1,160 kJ mol^-1
  B) 1,180 kJ mol^-1
  C) 1,560 kJ mol^-1
  D) 1,600kJ mol^-1
  E) 1,680 kJ mol^-1
  Show Answer
  The correct answer is E .
• Question 1578: Given that electronegativity increases across a period and decreases down a group in the periodic table, in which of the following compounds will the molecules be held together by the strongest hydrogen bond? Options:
  A) HF_(g)
  B) NH_3(g)
  C) CH_4(g)
  D) HCl_(g)
  Show Answer
  The correct answer is A .
• Question 1579:

  How many pi ($\pi$) bonds are there in an alkene with six carbon atoms?

  Options:
  A) 4
  B) 6
  C) 5
  D) 3
  Show Answer
  The correct answer is D .
• Question 1580:

  Consider the reaction: A + 2B${}_{(g)}\rightleftharpoons$ 2C + D${}_{(g)}$ ($\mathrm{\Delta }$H = +ve)

  What will be the effect of decrease in temperature on the reaction?

  Options:
  A) Rate of backward reaction will increase
  B) The equilibrium constant will shift
  C) Rates of forward and backward reactions are not affected
  D) Rate of forward reaction will increase
  Show Answer
  The correct answer is A .