question_answer 67)

  On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed. (a) Write a balanced chemical equation of the reaction. (b) Identify the brown gas X evolved. (c) Identify the type of reaction. (d) What could be the pH range of aqueous solution of the gas X?

Answer:

    (a) (b) X is nitrogen dioxide gas (NO2). (c) This is a thermal decomposition reaction. (d) The aqueous solution of the gas is acidic because it is an oxide of a non-metal, so its pH range would be in between 1 to 7.