Which of the following colloids are formed when hydrogen sulphide gas is passed through a cold solution of arsenious oxide?

Most suitable salt which can be used for efficient clotting of blood will be :-

Explain what is observed:
$(i)$ When a beam of light is passed through a colloidal sol.
$(ii)$ An electrolyte,$NaCl$,is added to hydrated ferric oxide sol.
$(iii)$ Electric current is passed through a colloidal sol.

Which of the following is an example of $water$ in $oil$ type emulsion?

Muddy water can be purified through coagulation using

Which of the following is an emulsifier?