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Chemistry 2021 WAEC Past Questions

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31

Student X titrated 25 cm\(^{3}\) of Na\(_{2}\)CO\(^{3}\) with 0.1 mol dm\(^{-3}\) HCI, using methyl orange as indicator. Student Y carried out the same exercise but used phenolphthalein as an indicator. Which of the following statements about the titration is true?

  • A. hydrogen chloride gas was released in the reactions in both titrations
  • B. the titer values obtained from the titration are equal
  • C. the titer value obtained by X is twice that of Y
  • C. the titer value obtained by Y is twice that of X
View Answer & Discuss (6) WAEC 2021
32

What is the concentration of a solution which contains 0.28g of potassium hydroxide in 100 cm\(^{3}\) of solution [KOH = 56]

  • A. 0.01 mol dm\(^{-3}\)
  • B. 0.05 mol dm\(^{-3}\)
  • C. 0.10 mol dm\(^{-3}\)
  • D. 0.50 mol dm\(^{-3}\)
View Answer & Discuss (3) WAEC 2021
33

What is the empirical formula of a hydrocarbon containing 0.160 moles of carbon and 0.640 moles of hydrogen

  • A. CH\(_{2}\)
  • B. CH\(_{3}\)
  • C. CH\(_{4}\)
  • D. C\(_{2}\)H\(_{4}\)
View Answer & Discuss (5) WAEC 2021
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34

Which of the following species has the largest ionic radius

  • A. S\(^{2-}\)
  • A. K\(^{+}\)
  • B. CI\(^{-}\)
  • D. Ca\(^{2+}\)
View Answer & Discuss (7) WAEC 2021
35

Which of the following statements is correct about ionization energy? It

  • A. decreases across the periods
  • B. results in the formation of an anion
  • C. causes Metalic nuclei to disintegrate
  • D. decreases down the group
View Answer & Discuss (4) WAEC 2021
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