Question

(a) Write three differences between
compound and mixture.
(b) What will happen if small amount of
dilute sulphuric acid is added to:
(i) a test tube containing a mixture of
iron and sulphur.
(ii) a test tube containing a
compound of iron and sulphur.​

Answer 1

Answer:

(a) The mixture contains two or more substances mixed, but neither chemically as well as not in inexact quantity while compound includes two or more elements combined chemically and in a fixed ratio. Pure substances are made up of elements and compounds. ..

(b) (i) The reaction between dil. sulphuric acid and sodium sulphite occurs in two steps and is a double replacement reaction.

In the first step, sulphuric acid reacts with sodium sulphite to give sodium sulphate and sulphurous acid.

H

2

SO

4

+Na

2

SO

3

→Na

2

SO

4

+H

2

SO

3

In the second step, sulphurous acid, which is highly unstable decomposes spontaneously into sulphur dioxide and water.

H

2

SO

3

→SO

2

+H

2

O

Thus, the overall reaction is written as:

H

2

SO

4

+Na

2

SO

3

→Na

2

SO

4

+SO

2

+H

2

O

(ii) ......