Observe the diagram given below used in the electrolysis of aqueous CuSO₄ solution. Study the diagram and answer the following.

(a) Write the equation for the reactions that is occurring at anode and cathode.

(b) State two appropriate observations for the given electrolysis reaction.

(c) Why does the blue colour of Cu²⁺ ions in the electrolytic solution fades slowly? Explain.

Which type of fumes are evolved when copper is added to acidified nitrates?

1. NO₂ fumes
2. N₂O fumes
3. N₂ fumes
4. N₂O₃ fumes

The molecular mass of CO₂ and O₂ are approximately 44 and 32 respectively. Which of the following statements regarding the mass of oxygen and number of molecules of oxygen is correct?

P. The mass of oxygen in 2.24 litres of CO₂ is 3.2 g

Q. The number of molecules of oxygen present in it is 6.022 x 10²³

1. Only P
2. Only Q
3. Both P and Q
4. Neither P nor Q

Complete the following by choosing the correct answer from the bracket.

(a) Alkenes differ from alkanes due to the presence of …………… (double/single) bonds.

(b) Down the group, ionisation potential …………… (increases /decreases).

(c) By dissolving aluminium oxide in cryolite a …………… (conducting/non-conducting) solution is produced.

(d) The catalyst used for conversion of ethene to ethane is commonly …………… (iron/nickel).

(e) The gas released when sodium carbonate is added to a solution of sulphur dioxide is …………… (CO₂/SO₃)