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Question
The action of heat on the blue crystalline solid X gives a reddish brown gas Y, a gas which re-lights a glowing splint and leaves a black residue. When gas Z, which has a rotten egg smell, is passed through a solution of X, a black ppt. is formed.
- Identify X, Y and Z.
- Write the equation for the action of heat on X.
- Write the equation between solution X and gas Z.
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Solution
a. X is copper nitrate [Cu(NO3)2].
Y is nitrogen dioxide [NO2].
Z is hydrogen sulphide [H2S].
b. \[\ce{\underset{Blue crystalline}{2Cu(NO3)2} ->[heat] \underset{Black}{2CuO} + 4NO2 + O2}\]
c. When a H2S gas, which has a rotten egg smell, is passed through a solution of Cu(NO3)2, a black ppt. of CuS is formed.
\[\ce{Cu(NO3)2 + H2S ->CuS + 2HNO3}\]
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