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 231:

  According to Charles' law, the volume of a gas becomes zero at

  Options:
  A) 0°C
  B) -100°C
  C) -273°C
  D) -373°C
  Show Answer
  The correct answer is C .
• Question 232:

  Which of the following is an example of a primary cell?

  Options:
  A) Alkaline battery
  B) Nickel-cadmium battery
  C) Lead-acid battery
  D) Lithium-ion battery
  Show Answer
  The correct answer is A .
• Question 233: The substance that is used in the steel industry for the removal of carbon. Sulphur and phosphorus impurities from pig iron is Options:
  A) oxygen
  B) chlorine
  C) nitrogen
  D) hydrogen
  Show Answer
  The correct answer is A .
• Question 234: 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 .
• Question 235:

  If the volume of a given mass of a gas at 0ºc is29.5cm${}^3$. What will be the volume of the gas at 15ºc, given that the pressure remains constant.

  Options:
  A) 31.6
  B) 62.2
  C) 32.7
  D) 31.1
  Show Answer
  The correct answer is D .
• Question 236:

  The combustion of carbon(ii)oxide in oxygen can be represented by equation.

  2CO + O${}_2$ → 2CO${}_2$

  Calculate the volume of the resulting mixture at the end of the reaction if 50cm${}_3$ of carbon(ii)oxide was exploded in 100cm${}_3$ of oxygen

  Options:
  A) 75cm${}^3$
  B) 125cm${}^3$
  C) 100cm${}^3$
  D) 50cm${}^3$
  Show Answer
  The correct answer is B .
• Question 237:

  Which group does calcium belong to in the periodic table?

  Options:
  A) Alkaline earth metals
  B) Halogens
  C) Alkali metals
  D) Noble gases
  Show Answer
  The correct answer is A .
• Question 238: In the laboratory preparation of chlorine from concentrated hydrochloric acid in the presence of potassuim tetraoxomanganate(VII) the produced is dried by passing it through Options:
  A) Concentrated tetraoxosulphate (VI) acid
  B) Anhydrous calcium chloride
  C) Calcium oxide
  D) Sodium hydroxide
  Show Answer
  The correct answer is A .
• Question 239: During a titration experiment, 0.05 moles of carbon (lV) oxide is liberated. What is the volume of gas liberated? Options:
  A) 22.40 dm ³
  B) 11.20 dm ³
  C) 2.24 dm ³
  D) 1.12 dm ³
  Show Answer
  The correct answer is D .
• Question 240:

  The enzyme that converts glucose to ethylalcohol is?

  Options:
  A) maltase
  B) zymase
  C) Diatase
  D) Invertase
  Show Answer
  The correct answer is B .