on heating copper powder in china dish the surface of copper sulphate solution and white precipiate is formed​

When barium chloride solution is mixed with copper sulphate solution and a white precipitate is observed. In double displacement reaction, a precipitate is formed which settles down at the bottom. Any reaction that produces a precipitate is called a precipitation reaction.

c (diamond),

sio2 (quartz)

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.