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Chemistry Past Questions and Answers

Neco Chemistry Questions

Question 76:
Which formula is used to indicate the degree of acidity of an acid?
  • A \( [H^+] = ^{\text{mass of acid relative}} molecular mass of acid \)
  • B F = number of H+ = ions x molar mass of the acid
  • C Kw = [H+][OH-]
  • D PH = - log10[H+]
  • E PKa = -log10Ka
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Question 77:
What is the IUPAC name of CH3CCI=C(CH3)2?
  • A 2-chloro -3 methylbut -2yne
  • B 2 -chloro -3 methylbut -2ene
  • C 2 -chloro -3 methylbutene
  • D 3- methyl -2-chlorobut -2-ene
  • E 3- methyl -2. chlorobut -2 yne
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Question 78:
What change will occur to the equilibrium mixture
\( 2CrO^{2-}_4(aq) + 2H^+(aq) ⇔ Cr_2O^{2-}_7(aq) + H_2O(l) \) when excess sodium hydrogen solution is added?
  • A A yellow precipitate of Cr(OH)3 is formed
  • B An orange precipitate of Cr(OH)3 is formed
  • C The colour changes from orange to yellow
  • D The colour changes from yellow to orange
  • E There is no visible reaction.
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Question 79:
Which element is the most electronegative?
  • A Calcium
  • B Fluorine
  • C Iodine
  • D Oxygen
  • E Sodium
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Question 80:
Which of the following compounds is unsaturated?
  • A Cyclohexane
  • B Methoxyethane
  • C 1 ,2-dibromoethane
  • D 2,2,3-trimethylpentane
  • E 3-methylbut-l-ene
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