Question

on heating blue coloured powder of copper(ii) nitrate in boiling tube copper oxide (black) oxygen gas and a brown gas'X' is formed (i) write the chemical equation of the reaction. (ii) identify the brown gas'X' evolved. (iii) identify the type of reaction (iv) whar could be the pH range of aqueous solution gas X​

Answer 1

CuNo3=CuO+NO2

NO2 is a brown gas.

This reaction is a decomposition reaction.

Answer 2

Answer:

(a) Cu(NO3)2 --------heat----->  2CuO         +     O2          +      4NO2

 copper (II) nitrate          copper oxide     oxygen gas      nitrogen dioxide

                                              (black)                                            (brown)

(b) X is nitrogen dioxide gas (NO2) that is evolved as brown, choking fumes.

(c) A thermal decomposition reaction.

(d) The aqueous solution of the NO2 forms nitrous acid and nitric acid so pH of solution would be less than 7 as medium will be acidic.