Question

A pinch of bread was placed inside a test tube and heated until it became

blackish in color and released some gas. Which of the following statement/s

is/are TRUE according to the given information?


I. Bread is solution.

II. Bread is composed of only one substance.

III. Bread is made up of solid and gaseous substances.

IV. Bread is made up of mixtures of different substances.

A. I only

B. II & III

C. II only

D. III & IV​

Answer 1

D.) III & IV are true. Bread is made up of solid and gaseous substances and bread is made up of mixtures of different substances.

Explanation:

• Bread is a mixture. Bread is formed by baking a mixture of flour, salt, yeast and water.

• In bread making, yeast organisms expel carbon dioxide when feeding on sugars. As the dough rises, carbon dioxide is formed; this is why the dough volume increases. Carbon dioxide expands and moves as the bread dough warms and bakes in the oven. The bread rises and sets.

• The mixture is a colloidal solution which acts as a dispersing medium as liquid.

• When it baked the yeast present in the mixture respire and release carbon dioxide which acts as a dispersed phase as gas. They together form bread.

Bread is a foam colloidal mixture.