Chemistry Past Questions and Answers

The movement of liquid molecules from the surface of the liquid to the gaseous phase above it is known as?

A Brownian movement
B Condensation
C Evaporation
D Liquefaction

Question 37:

What mass of a divalent metal M (atomic mass = 40) would react with excess hydrogen gas measured at S.T.P?

A 8.0 g
B 4.0 g
C 0.8 g
D 0.4 g

Question 38:

In the solubility curve above, water at 98^oC is saturated with KCL and KCIO ₃ What is the percentage of KCL impurity in the crystals formed when the solution is cooled to 30 ^oC?

A 51.5
B 45.5
C 34.5
D 26.5

Question 39:

In the electrolysis of aqueous solution of K₂SO ₄ in the above cell, which species migrate to the anode?

A SO^2-OH ^-
B K ⁺ and SO ₄^2-
C OH and HO
D H₃O ⁺ and K

Question 40:

The tabulated results below were obtained by titration 10.0 cm₃ of water with soup. The titration was repeated with the same sample of water after boiling. The ratio of permanent to temporary hardness is

A 1.5
B 1.4
C 4.1
D 5.1