Question

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Answer 1

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☆☆Answers of question no. 9 :--☆☆

1) When lead nitrate is heated, it melts and on further heating it gives out a reddish brown gas (NO2). A glowing splinter near the test tube, bursts into flame which proves that oxygen is mixed with the brown gas.


#Reaction:  2Pb(NO3)2 --> 2PbO + 4NO2 + O2.

2) When chlorine water, which is greenish yellow in colour, is exposed to sunlight, a colourless gas is evolved which rekindles a burning splinter and tue solution loses its colour

#Reaction: H20 + Cl2 --> 2HCl + O2

3) When colourless H2O2 is exposed to sunlight, it decomposes to form water and colourless gas which rekindles a glowing splinter. The solution left can turn colourless anhydrous CuSO4 blue.

#Reaction: 2H2O2 --> 2H2O +O2

4) When H2S gas is passed through blue CuSO4 solution , a black precipitate of CuS (copper sulphide) is obtained.

#Reaction: CuSO4 + H2S --> CuS + H2SO4

5) When barium chloride is added to colourless sodium sulphate solution, a white precipitate of barium sulphate is obtained, which is insoluble in acid.

#Reaction: BaCl2 + Na2SO4 --> BaSO4 + 2NaCl.

☆☆Answers of question no. 10 :--☆☆

1)A carbonate which does not decomposes on heating:
---- SODIUM CARBONATE (Na2CO3)

2)A nitrate which produces oxygen as the only gas:
---- POTASSIUM NITRATE (KNO3)

3) A compound which produces carbon dioxide on heating:
----CALCIUM CARBONATE (CaCO3)

4) A nitrate which produces brown gas on heating;
---- SILVER NITRATE (AgNO3)

***Hope it helps!***