CBSE Questions for Class 9 Chemistry Is Matter Around Us Pure Quiz 10 - MCQExams.com

Fractional distillation is the separation of a mixture into its parts, or fractions, separating chemical compounds by their boiling point by heating them to a temperature at which one or more fractions of the compound will vaporize. It uses the boiling point as a guide while separating one sample from another. 

Fractional distillation is the separation of a mixture into its component parts, or fractions, separating chemical compounds by their boiling point by heating them to a temperature at which one or more fractions of the compound will vaporize. It uses distillation to fractionate.

Option $$A$$ is correct.

The boiling point of a substance determines what component will separate out during the process of fractional distillation. It is used to separate a mixture of two or more miscible liquids for which the difference in boiling points is less than 25 K.

Fractional distillation is the separation method that is based on the different boiling points of the different components. Crude oil is a mixture of various components such as petroleum gas, petrol, diesel, paraffin wax, lubricating oil. 

The process of separating the various components of petroleum from one another is known as the refining of petroleum. This is done by the fractional distillation method.

The particle size of a true solution is less than $$1nm$$ in diameter. Neither visible by naked eyes nor by microscope.

The particle size of the colloidal solution is between $$1nm\ to \ 1000nm$$. Not visible by naked eyes but visible by electron or ultramicroscope.

A saturated solution is a type in which no more solute can be dissolved in the solvent.

The homogeneous solution has one phase whereas the heterogeneous solution has more than one phase. It may be a true or colloidal solution.

Changes in pressure do not affect the solubility of solids and liquids that we may ignore because the reason that compressibility of solid and liquid substances is almost negligible or very less as compare to gases so to make them soluble by increasing the pressure in liquid is not as easy as it is for the gases in liquid.   

• A colloid is a mixture in which one of the substances is split into very minute particles which are dispersed throughout a second substance. The substance which is dispersed is called a dispersed phase whereas the one in which the first substance is distributed is called a dispersion medium.
  
• The size of colloid particles generally ranges between 1 to 1000 nanometres i.e. $$10^{-5}$$ to $$10^{-7} cm$$.
  10−5 - 10−7 cm

Hint:

A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance

Explanation:

Depending upon the type of dispersion medium and the dispersed phase, colloids can be categorized into different types.

• Among which when a liquid substance is dispersed in a gas medium, the combination is called aerosols. Some examples are fog, cloud, mist, etc.
  
  
• When gas is dispersed in the liquid medium it is called foam. Some of the examples are shaving cream, egg white.
  
  
• When a solid is dispersed in the gas medium it is also called an aerosol. Dust is an example of this kind of sol.
  
  
• When gas is dispersed in a solid medium, it is called solid foam. Smoke is an example of solid foam.

Final answer:

Therefore, the correct answer is option A.