How is nitric acid prepared in laboratory?

Conc. nitric acid prepared in laboratory is yellow colour. Why? How is this colour removed ?

How is formic acid prepared ?

How is ammonia gas prepared in laboratory, starting from NH_4Cl ?

How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions involved.

How is dihydrogen prepared in laboratory ?

How is methane gas prepared in laboratory ?

How is acetylene gas prepared in laboratory?

How is benzene prepared in the laboratory? Write a note on its electrophilic substitution reactions.

State the colour of - (i) pure nitric acid (ii) nitric acid obtained in the laboratory (iii) nitric acid obtained in the laboratory after passage of air or addition of water to it .

How is benzene prepared in the laboratory and on commercial scale ? How does it react with ozone