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 681:

  

  How many more isomers of the compound above can be obtained ?

  Options:
  A) 5
  B) 4
  C) 3
  D) 2
  Show Answer
  The correct answer is B .
• Question 682: The mass of silver deposited when a current of 10A is passed through a solution of silver salt for 4830s is – (Ag = 108 F = 96500(mol^-1) Options:
  A) 54.0g
  B) 27.0g
  C) 13.5g
  D) 108.0g
  Show Answer
  The correct answer is A .
• Question 683: Cancerous growths are cured by exposure to Options:
  A) γ - rays
  B) β - rays
  C) α - rays
  D) x - ray
  Show Answer
  The correct answer is D .
• Question 684: The atom of an element X is represented as _z^yX. The basic chemical properties of X depends on the value of Options:
  A) Y
  B) Z
  C) Y - Z
  D) Z - Y
  Show Answer
  The correct answer is B .
• Question 685: A pair of compounds that can be used to generate a gas which has physiological effect on human beings is Options:
  A) sodium trioxonitrate (V) and calcium chloride
  B) sodium dioxonitrate (III) and ammonium chloride
  C) sodium trioxonitrate (V) and ammonium chloride
  D) sodium dioxonitrate (III) and potassium chloride
  Show Answer
  The correct answer is A .
• Question 686: Which of the following does NOT happen when a zinc rod is introduced into a solution of copper (ll) sulphate? Options:
  A) Electrons flow towards the zinc rod
  B) The zinc rod dissolves
  C) The temperature of the soil changes
  D) The blue colour of the solution gradually disappears
  E) Copper metal is deposited
  Show Answer
  The correct answer is A .
• Question 687: The electronic configuration of elements X and Y are X = 2, 8, 6; Y = 2, 8, 7. The bond in the compound formed by X and Y is expected to be? Options:
  A) ionic
  B) covalent
  C) dative covalent
  D) metallic
  E) none of the above
  Show Answer
  The correct answer is B .
• Question 688:

  What is the mass (in grams) of 500 mL of ethanol? (density of ethanol = 0.789 g/mL)

  Options:
  A) 394.5 mL
  B) 500 mL
  C) 394.5 g
  D) 500 g
  Show Answer
  The correct answer is C .
• Question 689: 0.07g of a hydride of carbon occupies 56.0cm³ at S.T.P. when vaporized and contains 14.29% by mass of hydrocarbon is(C = 12, H = 1) Options:
  A) CH₄
  B) C₂H₂
  C) C₂H₄
  D) C₂H₆
  E) C₃H₈
  Show Answer
  The correct answer is C .
• Question 690:

  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 .