Question

What is the $ \% \dfrac{V}{V} $ of a $ 5 $ $ litre $ petrol solution containing $ 750ml $ kerosene?

Answer 1

Hint: There are different methods of expressing the concentration of a solution, one of them is the volume per volume solution. This is used for the liquid solution. We can simply solve the question using the concentration formula.

Complete answer:
Concentration is marked as volume by volume, weight by weight or weight by volume. These are the expressions used to express the concentration whether it is liquid ( $ \dfrac{V}{V} $ ) or when solid is dissolved in liquid ( $ \dfrac{W}{V} $ )
The percentage solutions are in different forms, one of them is volume by volume percentage.it is calculated as the fraction of volume of the solute related to the total volume of the solution. In equation form it can be written as-
 $ volume{\text{ }}percentage = \dfrac{{volume{\text{ }}of{\text{ }}solute}}{{volume{\text{ }}of{\text{ }}solution{\text{ }}}} \times 100 $
The question states that $ 750ml $ of kerosene is diluted in $ 5 $ litre of petrol. Kerosene is the solution here and petrol is the solution.
To answer the above question, as the volume of solute as well as the volume of solution is given, we can simply put the values in the above formula.
Volume of solution = $ 5L = 5000ml $
Volume of solute = $ 750ml $
Putting the above value in volume percentage formula
 $ % \dfrac{V}{V} = \dfrac{{750}}{{5000}}}} \times 100 $
 $ % \dfrac{V}{V} = 15}} $
Therefore the volume percentage of the above-given question is $ 15 $
Volume percentage is a dimensionless quantity.

Note:
Students often get confused between solute, solvent, and solution. The solution is a homogenous mixture of two or more substances. A solution has a solvent and solute as its components. The component of the solution that dissolves the other component in it is called the solvent. The component of the solution that is dissolved in the solvent is called the solute.