Last updated on August 30th, 2023 at 01:00 am
- In a beaker, water is taken.
- Add a few drops of diluted sulphuric acid.
- As soon as it starts boiling, add copper sulphate powder slowly while stirring continuously.
- Copper sulfate powder is added to saturation level.
- Filter and cool the solution.
- Let it remain undisturbed for a few hours, then we’ll observe copper sulphate crystals.
Q9 :Explain how painting of an iron gate prevents it from rusting.
During rusting, both moisture (water) and air (oxygen) contribute to the process. Painting an iron gate prevents it from coming into contact with the air and moisture present in the atmosphere. Thus, rusting is prevented.
Q10 :Anaerobic bacteria digest animal waste and produce biogas (Change – A). The biogas is then burnt as fuel (Change – B). The following statements pertain to these changes. Choose the correct one.
(i) Process – A is a chemical change.
(ii) Process – B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change.
Answer :
(iii) Both processes A and B are chemical changes.
