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 1861:

  How many bonding pair are present in carbon(iv)oxide?

  Options:
  A) 4
  B) 3
  C) 2
  D) 1
  Show Answer
  The correct answer is A .
• Question 1862: Fats and oils are? Options:
  A) addition products of long chain fatty acids and alkali
  B) addition products of long-chain fattyy acids and glycerol
  C) condensation products of long-chain fatty acids and glycerol
  D) condensation products of formaldehyde and glycerol
  E) liquids at 20°C
  Show Answer
  The correct answer is C .
• Question 1863: The final products of the reaction between methane and chlorine in the presence of ultraviolet light are hydrogen chloride and Options:
  A) tricloromethane
  B) dichloromethane
  C) tetrachloromethane
  D) chloromethane
  Show Answer
  The correct answer is C .
• Question 1864:

  When 10g of sodium hydroxide is dissolved in 1000cm³ of water, the sodium formed is approximately

  [Na = 23, H = 1, O = 16]

  Options:
  A) 0.01 mol dm^-3
  B) 0.10 mol dm^-3
  C) 0.25 mol dm^-3
  D) 0.50 mol dm^-3
  Show Answer
  The correct answer is C .
• Question 1865:

  In the reaction N₂(g) + O(g) ↔ 2NO(g) produced an increase in the total pressure will?

  Options:
  A) cause less nitrogen to be produced in the equilibrium mixture
  B) cause less nitric oxide to be produced in the equilibrium mixture
  C) cause more nitric oxide to be produced in the equilibrium mixture
  D) cause more oxygen to be produced in the equilibrium mixture
  E) have no effect
  Show Answer
  The correct answer is E .
• Question 1866:

  For the general equation of the nature

  XP + yQ ⇌ mR + nS, the expression for the equilibrium constant is

  Options:
  A) k[P]${}^x$[Q]${}^y$
  B) $\frac{m[R][S]}{x[P]y[Q]}$
  C) $\frac{[P{]}^x[Q{]}^y}{[R{]}^m[S{]}^n}$
  D) $\frac{[R{]}^m[S{]}^n}{[P{]}^x[Q{]}^y}$
  Show Answer
  The correct answer is D .
• Question 1867: the vapour density of a gas may be defined as Options:
  A) the mass of a unit volume of the gas compared to an equal volume of water vapour
  B) the mass of a unit volume of the gas compared to an equal volume of hydrogen
  C) the mass of a unit volume of the gas compared to an equal volume of oxygen
  D) the mass of a unit volume of the gas minus the vapour pressure of water
  E) two times the relative molecular mass of the gas
  Show Answer
  The correct answer is B .
• Question 1868: Moving from left to right across a period, the general rise in the first ionization energy can be attributed to the Options:
  A) decrease in nuclear charge
  B) increase in nuclear charge
  C) decrease in screening effect
  D) increase in screening effect
  Show Answer
  The correct answer is B .
• Question 1869:

  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 1870: Water is said to be temporarily hard when it contains Options:
  A) Ca (HCO₃)₂ and Mg (HCO₃)₂ salts
  B) Ca (HCO₃)₂ and CaCO₃ SALTS
  C) Mg(HCO₃)₂ and CaSO₄ salts
  D) CaSO₄ and Ca(HCO₃)₂ salts
  Show Answer
  The correct answer is A .