Preparation of laboratory method from - KNO 3 , NaNo3 and conc H2SO4

Question 1

why concentrated H2so4 is used

Answer 1

Strong non volatile capable of displacing more volatile nitric acid

Question 2

Conc. HCL is not used why

Answer 2

being volatile itself can’t displace more volatile nitric acid

Question 3

complete apparatus is made of glass why ?

Answer 3

since vapours of nitric acid being highly corrosive

Question 4

at temp less than 200*C

Answer 4

NaNO3 + H2SO4 –> NaHSO4 + HNO3

Question 5

At temp above 200*C

Answer 5

NaNO3 + NaHSO4 –> Na2SO4 + HNO3

Question 6

High temp above 200 not used since

Answer 6

Damage to the glass apparatus
Further decomposition of the nitric acid
Formation of a hard residual crust of the corresponding sulphate which being a poor conductor of heat sticks to the glass and cannot be removed from the apparatus