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 961:

  The best treatment for a student who accidentally poured conc tetraoxosulphate(vi) on his skin in the laboratory is to wash his skin with?

  Options:
  A) with cool running water
  B) sodium hydroxide solution
  C) iodine solution
  D) sodium trioxonitrate(v) solution
  Show Answer
  The correct answer is A .
• Question 962: The pollutant that contributes to the depletion of the ozone layer is Options:
  A) CFCs
  B) NO₂
  C) SO₂
  D) CO
  Show Answer
  The correct answer is A .
• Question 963: When salt loses its water of crystallization to the atmosphere on exposure, the process is said to be Options:
  A) efflorescence
  B) déliquescence
  C) effervescence
  D) fluorescence
  Show Answer
  The correct answer is A .
• Question 964: Ethanol reacts with concentrated tetraoxosulphate (V) acid at a temperature above 170 ^oC to form Options:
  A) ethanone
  B) ethene
  C) ethyne
  D) ethanal
  Show Answer
  The correct answer is B .
• Question 965:

  Two cylinders A and B each contains 30 cm³ of

  Oxygen and nitrogen respectively at the same temperature and pressure. If there are 5.0 moles of nitrogen, then the mass of oxygen is?

  Options:
  A) 3.2 g
  B) 6.4 g
  C) 80.0 g
  D) 160.0 g
  Show Answer
  The correct answer is D .
• Question 966: Coal gas is made up of carbon (II) oxide, hydrogen and? Options:
  A) nitrogen
  B) air
  C) argon
  D) methane
  Show Answer
  The correct answer is D .
• Question 967:

  To what volume must 300cm${}^3$ of 0.60M sodium hydroxide solution be diluted to give a 0.40M solution?

  Options:
  A) 450cm${}^3$
  B) 300cm${}^3$
  C) 200cm${}^3$
  D) 150cm${}^3$
  Show Answer
  The correct answer is A .
• Question 968:

  CO_(g) + H₂ O_(g) → CO_2(g) + H_2(g)

  Calculate the standard heat change of the reaction above, if the standard enthalpies of formation of CO_2(g), H₂O_(g) and CO_(g) and CO_(g) in KJ mol ^-1 are - 394 -242 and - 110 respectively.

  Options:
  A) + 262 KJ mol ^-1
  B) - 262 KJ mol ^-1
  C) + 42 KJ mol ^-1
  D) - 42 KJ mol ^-1
  Show Answer
  The correct answer is D .
• Question 969:

  

  The I.U.P.A.C name for the compound is

  Options:
  A) isopropylethene
  B) acetylene
  C) 3- methylbutane
  D) 2-methylbutane
  E) 5-methylpentane
  Show Answer
  The correct answer is D .
• Question 970: Calculate the amount in moles of a gas which occupies 10.5 dm³ at 6 atm and 30^oC [R = 082 atm dm³ K^-1 mol^-1] Options:
  A) 2.536
  B) 1.623
  C) 4.736
  D) 0.394
  Show Answer
  The correct answer is A .