Question: On heating blue coloured powder of copper (II) nitrate in a boiling tube, black copper oxide, O2 and a brown gas X is formed.
(a) Identify the type of reaction and the gas X.
(b) Write balanced chemical equation of the reaction.
(c) Write the pH range of aqueous solution of the gas X. [CBSE OD, Set 1, 2019]
Answer: (a) Decomposition reaction The gas X is nitrogen dioxide (NO₂)
(b) 2Cu(NO₃)₂·3H₂O + ∆ → 2 CuO + 4 NO₂↑ + O₂↑ + 6H₂O
(c) Oxides of non-metals are acidic. Therefore aqueous solution of NO₂ would be acidic. The pH would be less than 7 or 6.9.
![Question: On heating blue coloured powder of copper (II) nitrate in a boiling tube, black copper oxide, O2 and a brown gas X is formed. (a) Identify the type of reaction and the gas X. (b) Write balanced chemical equation of the reaction. (c) Write the pH range of aqueous solution of the gas X. [CBSE OD, Set 1, 2019]](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhs2BZzTzM-1pQ9c8Jy7gVUEea4ERjDDyZeGMp1XpoHO2uCkxd-R3QdQ-HgbE3reR5YoSzSJu5aUTo3JZnqUVRbvU9XfIrA54iFHdJ-6txpyWM7PPAmr4idjWe0t0BvGdZ6cbdB3sSnDIabhy_LXW1bi3iO0dDVeQUpWMXsBk0ufhva6Z76LXAJivmp/s1920/On%20heating%20blue%20coloured%20powder%20of%20copper%20(II)%20nitrate%20in%20a%20boiling%20tube,%20black%20copper%20oxide,%20O2%20and%20a%20brown%20gas%20X%20is%20form.jpg "Question: On heating blue coloured powder of copper (II) nitrate in a boiling tube, black copper oxide, O2 and a brown gas X is formed. (a) Identify the type of reaction and the gas X. (b) Write balanced chemical equation of the reaction. (c) Write the pH range of aqueous solution of the gas X. [CBSE OD, Set 1, 2019]")