Chemistry Past Questions and Answers

Which of the following pieces of deposited if a current of 10A was passed through a solution of copper(ll) salt for 965 seconds? (1F = 96500 C)

A 0.005 mole
B 0.025 mole
C 0.05 mole
D 1.00 mole
E 1.05 mole

Question 262:

Some precious stones such as ruby and sapphire consist of aluminum oxide coloured by traces of the oxides of

A Group lV elements
B Group l metals
C Transition metals
D Alkaline earths
E The halogens

Question 263:

Consider the reaction represented by the following equation CaCI₂_(aq) + H ₂C₂O ₄_(aq) â‡Œ CaC ₂O₄_(s) + 2HCI_(aq). Which of the following would dissolve the precipitate of CaC ₂O₄ formed?

A Stirring the mixture vigorously
B Adding more calcium chloride solution
C Lncreasing the concentration of the ethanedioic acid
D Adding concentrated hydrochloric acid
E Adding some distilled water

Question 264:

The following gases decolorize bromine water except

A C₂H₆
B C₂H₄
C C₂H₂
D C₃H₄
E C₃H₆

Question 265:

What volume of distilled water should be added to 400cm3 of 2.0 mole dm-3 \(H_{2}SO_{4}\) to obtain 0.20 mole dm-3 of solution>

A 600cm-³
B 800cm-³
C 1,000cm-³
D 3,600cm-³
E 4,000cm-³