Chemistry Past Questions and Answers

Indicate which of the following statements is not true as we move from left to right along the periodic Table:

A Atomic number of elements increases
B Atomic mass of elements increases
C Electropositive character of elements increases
D Electronegative character of elements increases
E Number of electrons in the outermost orbits of element increases

Question 132:

0.1 Faraday of electricity was passed through a solution of copper (ll) sulphate. The maximum weight of copper deposited on the cathode would be [Cu = 64]

A 64.0g
B 32.0g
C 16.0g
D 6.4 g
E 3.2g

Question 133:

Which one of these compounds will NOT give an oxygen gas on heating?

A Manganese dioxide
B Hydrogen peroxide
C Zinc nitrate
D Sodium nitrate
E Ammonium nitrate

Question 134:

In the extraction of aluminum from purified bauxite by electrolysis, cryolite is used because

A It makes bauxite a better conductor of electricity
B It makes bauxite melt at a lower temperature
C It makes aluminium purer
D It prevents aluminium from getting oxidized
E It protects the carbon electrodes used in the process

Question 135:

In the redox reaction 2Fe2+ + CI2 â†’ 2Fe 3 + + 2Cl

A Cl2 is reduced because it has lost electrons
B Cl2 is reduced because its oxidation number has decreased
C Cl2 is reduced because its molecule is change to two ions
D Fe2+ is reduced because it has lost electrons
E Fe2+ is reduced because it has gained electrons