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 1321: When 50cm³ of a saturated solution of sugar (molar mass 342.0g) at 40^oC was evaporated to dryness, 34.2g of dry solid was obtained. The solubility of sugar at 40^oC is Options:
  A) 10.0 moles dm^-3
  B) 7.0 moles dm^-3
  C) 3.5 moles dm^-3
  D) 2.0 moles dm^-3
  Show Answer
  The correct answer is D .
• Question 1322: The filter in the cigarette reduces the nicotine content by Options:
  A) Burning
  B) Adsorption
  C) Evaporation
  D) Absorption
  Show Answer
  The correct answer is B .
• Question 1323: The label on a reagent bottle containing a clear organic liquid dropped off.The liquid was neutral to litmus and gave a colourless gas with metallic sodium. The liquid must be an? Options:
  A) alkanoate
  B) alkaene
  C) alkanol
  D) alkane
  Show Answer
  The correct answer is C .
• Question 1324: Methylethanoate reacts with ammonia to yield? Options:
  A) mettylamine and ethanol
  B) ethylamine and methanol
  C) methanamide and ethanol
  D) ethanamide and methanol
  Show Answer
  The correct answer is D .
• Question 1325: The reddish-brown rust on iron roofing sheets consists of Options:
  A) Fe³⁺(H₂O)₆
  B) FeO.H₂O
  C) Fe₂O₃.3H₂O
  D) Fe₃O₄.2H₂O
  Show Answer
  The correct answer is C .
• Question 1326:

  

  Use the option above to answer this question. The graph that describes a zero order reaction is

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .
• Question 1327: Which of the following compounds can be represented by the molecular formula C2 H6O? Options:
  A) propanal
  B) ethanol
  C) methanoic acid
  D) glucose
  Show Answer
  The correct answer is B .
• Question 1328: On cracking medicinal paraffin, a gas is evolved which gives a pop sound with a lighted splinter and an oily liquid which decolourizes bromine solution is also obtained. The products of the cracking are ? Options:
  A) carbon (IV) oxide and alkyne
  B) carbon (ll) oxide and alkene
  C) hydrogen gas and alkene
  D) hydrogen gas and alkane
  Show Answer
  The correct answer is C .
• Question 1329:

  During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment

  Options:
  A) the litmus turns blue but no gas is evolved
  B) the litmus turns blue and oxygen is evolved
  C) the litmus turns blue and hydrogen is evolved
  D) the litmus turns red and oxygen is evolved
  Show Answer
  The correct answer is D .
• Question 1330:

  When cathode rays are deflected onto the electrode of an electrometer, the instrument becomes?

  Options:
  A) Bipolar
  B) Negatively charged
  C) Positively charged
  D) Neutral
  Show Answer
  The correct answer is B .