Advertisements
Advertisements
Question
Give reason why concentrated nitric acid prepared in the laboratory is yellow in colour. State how the colour of the acid is removed.
Advertisements
Solution
The acid prepared in the laboratory decomposes slightly due to heat, releasing brown nitrogen dioxide (NO2) gas. This gas dissolves back into the acid, giving it a yellow colour.
\[\ce{4HNO3 ->[\Delta] 2H2O + 4NO2 + O2}\]
The yellow colour can be removed by bubbling dry air or carbon dioxide (CO2) gas through the acid to drive out the dissolved NO2, or by adding a little water, which converts the NO2 back into nitric acid.
APPEARS IN
RELATED QUESTIONS
Give a balanced chemical equation for Action of conc. Nitric acid on Sulphur
In the preparation of nitric acid from KNO3 concentrated sulphuric acid is used in place of hydrochloric acid. Why?
Nitric acid cannot be concentrated beyond 68% by the distillation of a dilute solution of HNO3. State the reason.
Write a balanced equation and name the products formed when sodium hydrogen carbonate is added to nitric acid.
Name the Following:
Product obtained by the catalytic oxidation of ammonia.
Write the balanced equation for the following:
Action of heat on AgNO3
Write equation to show the reaction between the following:
Copper and concentrated nitric acid.
Fill in the blank using the appropriate words given below:
Hot, concentrated nitric add reacts with sulphur to form ______.
What happens when
Caustic soda solution is added to Cu(NO3)2 solution and product boiled.
The diagram given below is a representation of the Industrial preparation of Nitric acid by Ostwald’s process. With respect to the process answer the following questions:
- Write the temperature and the catalyst required during the catalytic oxidation of ammonia.
- Give balanced chemical equation for the reaction occurring duringthe conversion of nitrogen dioxide to nitric acid.
