Search SchoolNGR

Friday, 19 June 2026
Register . Login

Chemistry Past Questions and Answers

Topic: Separation of mixtures and purification of chemical substances

Jamb Chemistry Questions - Separation of mixtures and purification of chemical substances

Question 386:
X is a substance which liberates CO\(_2\) on treatment with concentrated H\(_2\)SO\(_4\). A warm solution of X can decolorize acidified KMnO\(_4\). X is
  • A HCOOH
  • B NaHCO\(_3\)
  • C FeCO\(_3\)
  • D H\(_2\)C\(_2\)O\(_4\)
View Answer & Explanation
Question 387:
The cost of discharging 6.0g of a divalent metal, X from its salt is ₦12.00. What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?
[X = 63, Y = 27, 1F = 96,500C]
  • A N12.00
  • B N27.00
  • C N63.00
  • D N95.00
View Answer & Explanation
Question 388:
How many alkoxyalkanes can be obtained from the molecular formula C\(_4\)H\(_{10}\)O?
  • A 4
  • B 2
  • C 1
  • D 3
View Answer & Explanation
Question 389:
A solution X, on mixing with AgNO\(_3\) solution gives a white precipitate soluble in aqueous NH\(_3\), a solution Y, when also added to X, also gives a white precipitate which is soluble when heated solutions X and Y respectively contain
  • A Al\(^{3+}\), Cl\(^-\)
  • B Hg\(^+\), SO\(_4 ^{2-}\)
  • C Pb\(^{2+}\), Cl\(^-\)
  • D Ag\(^+\), SO\(_4 ^{2-}\)
View Answer & Explanation
Question 390:
An element Z contains 80% of \(^{16} _8\)Z and 20% of \(^{18} _8\)Z. Its relative atomic mass is
  • A 16.2
  • B 17.6
  • C 16.0
  • D 16.4
View Answer & Explanation