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 991:

  An organic compound which liberate carbon(iv)oxide from trioxocarbonate(iv) solution is likely to be?

  Options:
  A) C${}_2$H${}_5$OH
  B) C${}_3$H${}_4$
  C) C${}_6$H${}_6$
  D) CH${}_3$COOH
  Show Answer
  The correct answer is D .
• Question 992: In the reaction 1O^-₃ + 5l^- + 6H⁺ → 31₂ + 3H₂O, the oxidizing agent is? Options:
  A) H⁺
  B) l^-
  C) 1O^-
  D) l₂
  Show Answer
  The correct answer is C .
• Question 993:

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. At room temperature (300 K)

  Options:
  A) Y is twice as soluble as X
  B) X is twice as soluble as Y
  C) X and Y are soluble to the same extent
  D) X is three times as soluble as Y
  E) Y is three times as soluble as X
  Show Answer
  The correct answer is A .
• Question 994:

  P_(g) + Q_(g) ↔ 3R_(s) + S_(g) ΔH is negative

  Which of the following will increase the yield of R?

  Options:
  A) Using a larger close vessel
  B) Increasing the temperature
  C) Removing some S
  D) Adding a positive catalyst
  Show Answer
  The correct answer is C .
• Question 995: Hydrogen can be displaced from a hot alkaline solution by Options:
  A) Fe
  B) Cu
  C) Ca
  D) Sn
  Show Answer
  The correct answer is A .
• Question 996:

  The ions X_- and Y₊ are isoelectronic, each containing a total of 10 electrons.

  How many protons are in the nuclei of the neutral atoms of X and Y respectively?

  Options:
  A) 10 and 10
  B) 9 and 9
  C) 11 and 9
  D) 9 and 11
  Show Answer
  The correct answer is D .
• Question 997: An elements X with relative atomic mass 16.2 contains two isotopes ¹⁶₈X with relative abundance of 90% and ^m₈X with relative abundance of 10%. The value of m is Options:
  A) 16
  B) 18
  C) 12
  D) 14
  Show Answer
  The correct answer is B .
• Question 998:

  What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

  [H = 1, O = 16]

  Options:
  A) 36.0g
  B) 8.0g
  C) 72.0g
  D) 16.0g
  Show Answer
  The correct answer is C .
• Question 999:

  

  The above orbital diagram shown the electronic configuration of

  Options:
  A) chlorine
  B) nitrogen
  C) calcium
  D) neon
  Show Answer
  The correct answer is B .
• Question 1000:

  The molar ratio of carbon to hydrogen of a volatile liquid compound is 1: 2. 0. 12 g of the liquid on evaporation at s.t.p. gave 32 cm³ of vapour. The molecular formula of the liquid is

  [G.M.V =22.4 dm ³, C = 12, H = 1]

  Options:
  A) C ₃ H ₆
  B) C ₄H ₈
  C) C ₅C ₁₀
  D) C ₆H ₁₂
  Show Answer
  The correct answer is D .