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 1121: The elements that belong to the third period of periodic table are Options:
  A) Li, Be, Al and D
  B) Na, P, O and Cl
  C) B, C, N, and O
  D) N2, Mg, S and Ar
  Show Answer
  The correct answer is D .
• Question 1122: A gas exerts pressure on its container because Options:
  A) some of its molecules are moving faster than others
  B) of the collision of the molecules with each other
  C) of the mass of the molecules of gas
  D) the molecules of a gas colide with the walls of the container
  Show Answer
  The correct answer is D .
• Question 1123:

  

  The solubility curves of four substances are shown in the figure above. Which of the four substances would crystallize from a saturated solution cooled from 353K(80^oC)to 323K(50C)?

  Options:
  A) P and Q
  B) P and R
  C) P and S
  D) R and S
  E) Q and R
  Show Answer
  The correct answer is D .
• Question 1124:

  An example of a polysaccharide is?

  Options:
  A) Dextrose
  B) Mannose
  C) Glucose
  D) Starch
  Show Answer
  The correct answer is D .
• Question 1125:

  

  In the above set up substances X and Y are respectively

  Options:
  A) lime water copper (ll) tetraoxosulphate (lV)
  B) potassium trioxocarbonate and alkaline pyrogallol
  C) potassium hydroxide and alkaline pyrogallol
  D) potassium trioxocarbonate (lV) and concentrated tetraoxosulphate (IV) acid
  Show Answer
  The correct answer is C .
• Question 1126:

  

  From the diagram above the mass of crystals deposited when 1 dm ³ of a saturated solution of NaCl is cooled from 80^oC to 60^oC is

  [Na = 23, Cl = 35.5]

  Options:
  A) 117.00 g
  B) 58.50 g
  C) 11.70 g
  D) 5.85 g
  Show Answer
  The correct answer is A .
• Question 1127: When plastics and packaging materials made from chloroethene are burnt in the open, the mixture of gases released into the atmosphere is most likely to contain? Options:
  A) ethane
  B) chlorine
  C) hydrogen chloride
  D) ethene
  Show Answer
  The correct answer is C .
• Question 1128:

  The electronic configuration of an element is 1S${}^2$ 2S${}^2$ 2P${}^6$ 3S${}^2$ 3P${}^3$. How many unpaired electrons are there in the element?

  Options:
  A) 5
  B) 4
  C) 3
  D) 2
  Show Answer
  The correct answer is C .
• Question 1129:

  

  Which of the following compounds is a secondary alkanol?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 1130:

  A cell shorthand notation can be written as A / A${}^{+}$ // B${}^{2+}$ /B. The double slash in the notation represents the 

  Options:
  A) electrolyte
  B) electrodes
  C) salt bridge
  D) solid - liquid interface
  Show Answer
  The correct answer is C .