Observations That Helps Determine Chemical Rxn

Q.

What change in color is observed when copper sulfate is heated? Is it a chemical change or a physical one?

Q.

Name the various characteristics which indicate that a chemical reaction is taking place.

Q.

State the visible changes and give equations for reactions, when :

A piece of Na is added to cold water⇡

Q.

When washing soda is treated with hydrochloric acid, it gives off colourless gas with lot of effervescence, then that gas is

1. $C{O}_2$

2. $O_2$

3. $CO$

4. $C{l}_2$

Q.

White silver chloride in sunlight turns to

1. grey

2. yellow

3. remain white

4. red