2021 SCIENCE QUIZ - CHEMISTRY

The complete ionization of tetraoxosulphate(VI) acid produces

• 2H + SO₄

• H⁺ + SO₃^2-

• 2H⁺ + SO₄^2-

• 2H⁺ + SO₃^2-

What is the formula of a compound formed when an element Y with atomic number 13 combines with another element Z with atomic number 8?

• YZ₂

• YZ

• Y₃Z₂

• Y₂Z₃

What mass in grams of copper would be deposited in a copper voltammeter if 5,000 C of electricity was passed? [Cu = 63.5, IF = 96500C]

• 5.00

• 3.35

• 2.50

• 1.65

The final product of the reaction between C₂H₅OH and concentrated H₂SO₄ at 170⁰C is

• CH₃CH₂HSO₄

• CH₂ = CH₂

• CH ≡ CH

• (C₂H₅)₂SO₄

How many moles are present in 80g of CaCO₃? [Ca = 40, C = 12, O = 16]

• 1.0

• 0.8

• 0.6

• 0.4

240dm³ of air at s.t.p is compressed to 17 atmosphere in a compression tube. Determine the volume in dm³ occupied in the tube.

• 257

• 223

• 24

• 14

During the extraction of sodium using Downs cell, the anode is a/an

• steel cylinder

• iron rod

• iron lining of the container

• graphite rod

The following are sourced from petroleum industry except

• polyvinyl chloride

• pitch

• latex

• ligroin

The chemical formula of magnetite is

• FeS

• FeCO₃

• Fe₃O₄

• Fe₂O₃.H₂O

Water collected from rivers and ponds contain oxygen, carbon(IV) oxide and

• sulphur(VI)oxide

• nitrogen

• hydrogen

• helium