Question

Il- choose the correct option: 1. The reason for a physical change to be named as such is that the: (a) change occurs only in physical properties (b) transfer of energy takes place (c) is a reversible change (d) All of the above 2. Crystals of copper sulphate are prepared by the method of (a) Fractional distillation (b) Distillation (c) Solidification (d) Crystallization​

Answer 1

Answer:

1) d) all of the above

2)d)Crystallization​

Explanation:

1)A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.

2)How to prepare crystals of copper sulphate ?

Take a clean beaker (250 ml) and put the powdered impure sample of copper sulphate in it.

Add distilled water and stir the contents gently with the help of a glass rod.

In order to make the solution more clear add two or three drops of concentrated sulphuric acid in it.  

Heat the solution in the beaker to 60-70 0 C on a wire gauze.