Which of the following methods may be used to prepare trioxonitrate (V) acid (nitric acid) in the laboratory?

A.

Heating ammonia gas with tetraoxosulphate (VI) acid

B.

Heating ammonium trioxonitrate (V) with tetraoxosulphate (VI) acid

C.

Heating sodium trioxonitrate (V) with tetraoxosulphate (VI) acid

D.

Heating potassium trioxonitrate (V) with calcium hydroxide

E.

Heating a mixture of ammonia gas and oxygen.

Correct answer is C

No explanation has been provided for this answer.