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 271: Increasing the pressure of a gas Options:
  A) lowers the average kinetic energy of the molecules
  B) decreases the density of the gas
  C) decreases the temperature of the gas
  D) increases the density of the gas
  E) increases the volume of the gas
  Show Answer
  The correct answer is D .
• Question 272: Sodium and potassium belong to the same group of the Periodic Table. This is because? Options:
  A) both are metals
  B) both are soft and lighter than water
  C) both form cations by losing electrons
  D) both have identical electronic configuration
  E) both react with water vigorously
  Show Answer
  The correct answer is D .
• Question 273: Which of the following metals is the least reactive? Options:
  A) Pb
  B) Sn
  C) Hg
  D) Au
  Show Answer
  The correct answer is D .
• Question 274: The colour of methyl orange in alkaline medium is Options:
  A) yellow
  B) pink
  C) orange
  D) red
  Show Answer
  The correct answer is A .
• Question 275: Which of the following metals will liberate hydrogen from steam or dilute acid? Options:
  A) Copper
  B) Iron
  C) Lead
  D) Mercury
  Show Answer
  The correct answer is B .
• Question 276: 200 cm³ of a gas at 25^oC exerts a pressure of 700 mmHg. Calculate its pressure if its volume increase 350 cm³ at 75^oC. Options:
  A) 342.53 mmHg
  B) 1430.54 mmHg
  C) 467.11 mmHg
  D) 400.00 mmHg
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  The correct answer is C .
• Question 277: Tartaric acid is used industrially to Options:
  A) make baking powder
  B) make fruit juices
  C) remove rust
  D) dry substance
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  The correct answer is A .
• Question 278:

  The knowledge of half-life can be used to

  Options:
  A) Create an element
  B) Detect an element
  C) Split an element
  D) Irradiate an element
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  The correct answer is C .
• Question 279: Which of the activities is commonly used as a nuclear fuel Options:
  A) uranium
  B) palladium
  C) actium
  D) thorium
  Show Answer
  The correct answer is A .
• Question 280: A student prepares 0.5 M solution each of hydrochloric and ethanoic acids and then measured pH. The result would show that the? Options:
  A) pH values are equal
  B) HCI solution has a higher pH
  C) sum of the values is 14
  D) ethanoic acid solution has a higher pH
  Show Answer
  The correct answer is D .