Chemistry Past Questions and Answers

The greater the different in electronegativity between bonded atoms, the?

A Lower the polarity of the bond
B Higher the polarity of the bond
C Weaker the bond
D Higher the possibility of the substance formed being a molecule

Question 22:

A stream of air was successively passed through three tubes X, Y and Z containing a concentrated aqueous solution of KOH, red hot copper powder and fused calcium chloride respectively. What was the composition of the gas emanating from tube Z?

A CO₂ ad ithe inert gases
B N₂, CO₂ and the inert gases
C N₂ and the inert gases
D Water vapour, N₂ and the inert gases

Question 23:

In the purification of town water supply, alum is used principally to?

A Kill bacteria
B Control the pH of water
C Improve the taste of the water
D Coagulate small pasrticles of mud

Question 24:

Which of the following water samples will have the highest titre value when titrated for the Ca²⁺ ions using soap solution?

A Permanently hard water after boiling
B Emporarily hard water after boiling
C Rain water stored in a glass jar for two years
D Permanent hard water passed through permuitit

Question 25:

Oil spillage in ponds and creeks can be cleaned up by?

A Burning off the oil layer
B Spraying with detergent
C Dispersal with compressed air
D Spraying with hot water