Question

D. Write the effects of heat on the following:
1. Heating of orange coloured ammonium dichromate.
2. Action of heat on copper sulphate pentahydrate
3. Action of heat on silver nitrate
4. Action of heat on sodium hydroxide
5. Action of heat on nitrogen tetroxide.​

Answer 1

Answer:

1.At room temperature and pressure, it is orange, acidic crystal soluble in water and alcohol. On heating Ammonium dichromate, it undergoes decomposition, resulting in chromium (III) oxide and nitrogen gas formation. (NH4)2Cr2O7(s) → Cr2O3(s) + N2 (g) + 4H2O (g).

2.When copper sulphate pentahydrate is heated it looses the water molecules (dehydration) takes place which results in the loss of Blue colour of Copper sulphate.

3.Silver nitrate decomposes when heated: 2 AgNO3(l) → 2 Ag(s) + O2(g) + 2 NO2(g) ... Most metal nitrates thermally decompose to the respective oxides, but silver oxide decomposes at a lower temperature than silver nitrate, so the decomposition of silver nitrate yields elemental silver instead.

4.When heated, the solid dihydrate might melt directly into a solution at 13.35 °C; however, once the temperature exceeds 12.58 °C. it often decomposes into solid monohydrate and a liquid solution.

5.Power generation using N2O4

"Cool" dinitrogen tetroxide is compressed and heated, causing it to dissociate into nitrogen dioxide at half the molecular weight.