Search SchoolNGR

Sunday, 21 June 2026
Register . Login

Chemistry Past Questions and Answers

Topic: Avogadro's law

Jamb Chemistry Questions - Avogadro's law

Question 16:
the number of atoms in one mole of a substance is equal to?
  • A The atomic number
  • B The avogadro number
  • C The gas constant
  • D The number of neutrons
  • E The number of electrons
View Answer & Explanation
Question 17:
If 48,000 coulombs of electricity are required to discharge 0.5 mole of sodium from a molten sodium chloride mass, then the number of coulombs required to discharge 2 moles of lead from molten lead (ll) chloride is?
  • A 48,000
  • B 96,000
  • C 192,000
  • D 384,000
  • E 576,000
View Answer & Explanation
Question 18:
If one mole of aluminium contains 6 x 1023 atoms of aluminium, how many atoms are contained in 0.9g of aluminium?
(Al = 27)
  • A 1.0 x 10<sup style='font-size: smaller;'>21</sup>
  • B 6.6 x 10<sup style='font-size: smaller;'>21</sup>
  • C 2.0 x 10<sup style='font-size: smaller;'>22</sup>
  • D 1.0 x 10<sup style='font-size: smaller;'>22</sup>
  • E 5.4 x 10<sup style='font-size: smaller;'>23</sup>
View Answer & Explanation
Question 19:
4g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q.
Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?
  • A There were more aluminium atoms in Q than P
  • B The heat given off in retarded the reaction
  • C Q generated more pressure than P during the reaction
  • D P generated more pressure than Q
  • E Q has a greater surface area for the reaction than P
View Answer & Explanation
Question 20:
What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?
  • A All the nitrate will decompose to their respective metals
  • B The nitrates of calcium and potassium will decomposes to their nitrites
  • C Only copper nitrate decomposes to the metal
  • D Only the nitrates of zinc and copper will decompose to their oxides
  • E The nitrates of calcium, zinc and copper decompose to their oxides
View Answer & Explanation