Explanation:
STEP 1- Take two iron nails.
STEP 2- Clean it with sand paper.
STEP 3- Wrap copper wire around both the nails. And connect the other end to the battery terminal.
STEP 4- Take water in beaker and little amount of salt in it or a few drpos of sulphuric acid in it.
STEP 5- Immerse the nails in the solution.
STEP 6- Observe the nails carefully. You can see bubbles of gases coming out from water near nails.
When, electeric current is passed through water gases like hydrogen and oxygen are evolved.
2.Three things are required in proper combination before ignition and combustion can take place---Heat, Oxygen and Fuel. There must be Fuel to burn. There must be Air to supply oxygen. There must be Heat (ignition temperature) to start and continue the combustion process.
When iron is placed in Copper sulphate solution, the iron is coated with a brown coloured substance "copper" and CuSo4 solution changes from blue to light green. This is due to iron displaces copper as it is more reactive than copper.
