Detailed Study:

Frequently Tested Topics:

  • Equations and observations (gas evolved) for reaction of HNO3 with dilute and concentrated nitric acid 

  • Laboratory Preparation - equations, give reasons

  • Ostwald's Process 

  • Oxidising property of HNO3 - equations, observations

List of All Important Equations for HNO3

Important Past Questions:

  • Write balanced chemical equations for the following reactions:

i) Sulphur and hot concentrated nitric acid. (2005, 2017)

ii) Dilute nitric acid with copper. (2005, 2008, 2017)

iii) Decomposition of nitric acid. (2007)

iv) Copper is oxidized by concentrated nitric acid (2007, 2014, 2016)

v) Oxidation of carbon with concentrated nitric acid (2013)

vi) Laboratory preparation of nitric acid. (2014, 2017)

  • In what way is dilute nitric acid different from other acids when it reacts with metals?

(2005, 2015)

  • What is the property of nitric acid that allows it to react with copper? 


  • Give reasons:

i) A yellow colour appears in conc. nitric acid when left standing in an ordinary glass bottle. (2002, 2005, 2015)

ii) Only all glass apparatus should be used for the preparation of nitric acid by heating conc. sulphuric acid and potassium nitrate. (2006, 2015, 2018)

  • State the observations when:

i) Nitric acid is kept in a reagent bottle for a long time. (2006)

ii) Copper is heated with concentrated nitric acid by Ostwald's process. (2011)

  • Name the gas evolved in the following reactions:

i) Action of dilute nitric acid on copper. (2009, 2018)

ii) Copper reacts with concentrated nitric acid. (2012)

iii) Sulphur is treated with concentrated nitric acid. (2013, 2018)

  • Correct the statement by adding the missing word/s:

Copper reacts with nitric acid to produce nitrogen dioxide.


  • Fill in the blanks:

i) Cold, dil. nitric acid reacts with copper to form ________ [hydrogen, nitrogen dioxide, nitric oxide] (2014, 2016)

ii) Hot concentrated nitric acid reacts with sulphur to form ________ [sulphur dioxide, nitrogen dioxide, nitric oxide, sulphuric acid] (2016)

  • In the laboratory preparation of nitric acid:

i) Name the reactants A [a liquid] and B [a solid] used. (2007)

ii) State the special feature of the apparatus used in the laboratory preparation of nitric acid. (2011)

iii) State why the temperature of the reaction mixture of HNO3 is not allowed to rise above 200°C. (2011)

iv) State the type of salt formed. (2018)

  • Identify the acid:

i) a dilute acid which does not normally give hydrogen when reacted with metals but does give a gas when it reacts with copper. (2008)

ii) The acid which is prepared by catalytic oxidation of ammonia. (2015)

  • Choose the correct answer:

i) A non-metal which reacts with concentrated nitric acid to form its own acid as one of the products.

A] Sulphur B] Silver chloride C] Hydrogen chloride D] Copper [II] sulphate E] Graphite (2009)

ii) A catalyst used in the manufacture of nitric acid by Ostwald's process.

Acetylene gas, aqua fortis, coke, brass, barium chloride, bronze, platinum. (2011)

  • Copy and complete the following table relating to an important industrial process.

Name of Process          Inputs          Catalyst           Equation for Catalyzed reaction         Output

                             Ammonia + air                                                                               Nitric acid