What is produced at the cathode during the electrolysis of aqueous $Na_2SO_4$?

Which among the following is correct for the electrolysis of brine solution?

Which one of the following metals cannot be obtained on electrolysis of aqueous solution of its salts?

What products are formed during the electrolysis of a concentrated aqueous solution of $NaCl$?
$I. Cl_{2(g)}$
$II. NaOH_{(aq)}$
$III. H_{2(g)}$

Write the reactions for the following electrolytic processes:
$A$. Electrolytic reaction of concentrated aqueous solution of $NaCl$ (Brine).
$B$. Electrolytic reaction of dilute aqueous solution of $NaCl$.

When an electric current is passed through a cell containing an electrolyte,positive ions move towards the cathode and negative ions move towards the anode. If the cathode is removed from the solution,what will happen?