Let's address each question one by one:
vii. A certain liquid dissolves copper (II) sulphate to form a blue solution. This is likely to be:
C. Water
Copper (II) sulfate dissolves in water to form a blue solution.
viii. Classification of fuels based on the state includes:
B. Solid, gaseous and liquid fuels
Fuels can be classified into three main states: solid (e.g., coal), liquid (e.g., petrol), and gas (e.g., natural gas).
ix. The process of chlorination in water treatment aims at:
C. Killing micro-organism
Chlorination is primarily used to disinfect water by killing harmful microorganisms.
x. Addition of potash or Aluminum alum during urban water treatment is purposely for:
C. Coagulating solid particles
Aluminum alum acts as a coagulant, helping to clump together suspended particles in water to facilitate their removal.
Feel free to ask more questions if you have any!