what is aim of activity 2.15 class 10th chemistry
Answers
Explanation:
Activity 2.15 Class 10 Science, Chapter 2 Acids, Bases, and Salts
Heating of blue-vitriol in a test tube.
Brief Procedure:
Activity 2.15 asks us to heat copper sulphate and then add water to it and observe the change in the colour.
Observation:
Copper sulphate is usually blue when kept in a room.
On heating, copper sulphate becomes colourless and we also see a few drops in the test tube.
When we add water to the heated test tube, copper sulphate restore its colour and become blue again.
Explanation:
Copper sulphate absorbs moisture from the air and forms its hydrate (CuSO4.5H2O). The hydrate of copper sulphate is blue. So, we also call copper sulphate as blue vitriol.
When we heat copper sulphate its water of hydration goes away, and the substance becomes colourless.
When we add water, dehydrated copper sulphate regains its water of hydration and becomes blue.
Inference:
This experiment shows that
a crystal which looks solid in normal condition may not be dry as well. It may contain some other molecules attached to it.
These molecules may give the crystal different physical and chemical properties like the colour.
Aim of the experiment 2.15: Heating of blue-vitriol in a test tube.
Brief Procedure:
In Activity 2.15, we'll heat copper sulphate, then add water and see the colour change.
Observation:
- When kept in a room, copper sulphate is usually blue.
- Copper sulphate turns white when heated, and a few droplets appear in the test tube.
- Copper sulphate regains its colour and becomes blue when water is added to the heated test tube.
Explanation:
- Copper sulphate forms its hydrate by collecting moisture from the surrounding environment (CuSO₄.5H₂O). The colour of copper sulphate hydrate is blue. Blue vitriol is another name for copper sulphate.
- When copper sulphate is heated, the water that hydrates it evaporates, resulting in a colorless substance.
- When water is introduced to dehydrated copper sulphate, it rehydrates and becomes blue.
Inference:
- This experiment demonstrates that a crystal that seems solid under typical circumstances may not be completely dried. It may be connected to other molecules.
- These molecules may impart physical and chemical characteristics to the crystal, such as color.