Is Matter Around Us Pure Test - 57

Steam distillation is a method for heat-sensitive distilling compounds. This method is used to separate substances that are steam volatile and are immiscible with water. 

The liquids boiling under ordinary conditions of temperature and pressure without decomposition and containing non-volatile impurities are purified by simple distillation. However, to use this method the boiling points of liquids should differ greatly for efficient separation.  

Distillation is used to separate components of a mixture containing two miscible liquids that boil without decomposition and have sufficient difference in their boiling points. If the difference in boiling points is less than 25 K, fractional distillation is used for separation.

The composition of the homogenous solution is uniform throughout the solution whereas, the composition of the heterogenous solution is not uniform. Components of muddy water, bread, and concrete are not uniformly distributed in the solutions whereas, sugar is completely soluble in water and forms a homogeneous solution. Hence option D is correct.

• Milk is not a suspension as the particles in milk do not settle down when kept undisturbed over a period of time. Its particle size is much smaller than that of suspensions. 
• It is a colloid of liquid-liquid type, where fat is dispersed in water. 
• It is not a true solution because it is not homogeneous. 
• Also, it is not an alloy. Alloys are mixtures made of metals combined with other elements.

Tyndall effect refers to the process by which light is scattered by colloids or suspension making the path of the light to be visible. In the forests, the air contains mists that act as the colloids hence when light seeps in through the canopy one clearly sees its path.

Hence, option $$B$$ is correct.

The sugar can be separated from the sugar solution by the process of distillation, this process separates compounds based on the difference in their boiling point.

Distillation involves heating of the mixture of two miscible liquids. One liquid vaporises and then condenses in the condenser. It is then collected from the condenser outlet. So, distillation involves both evaporation and condensation.

Camphor converts directly into its gaseous state without converting into a liquid state. This phenomenon is called sublimation. Hence, when it's kept in open its quantity keeps on decreasing as it converts to its gaseous state.