Question

Q. 39 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 1

Answer:

On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas(X) and a brown gas Y is formed.

The chemical reaction involved and the balanced chemiacal equation is :

2Cu(NO

3

)

2 (S)

Heat

2CuO

(S)

+4NO

2(g)

+O

2(g)

The product formed are copper oxide(black), nitrogen dioxide(brown) and oxygen gas(colourless gas).

Answer 2

a) The reaction is

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

b) The brown gas is nitrogen dioxide .

c) This is a decomposition reaction.

d) NO2 is the oxide of non metal Nitrogen.

Since nonmetal oxides are acidic in nature, therefore the aqueous solution is acidic and pH between 0 to 6 and colour in pH paper will be between Dark red to yellow.

i hope it help.......