Which of the following is/are the method(s) of expressing the concentration of solution?

All of these

The correct answer is option 4. All of these.

The concentration of a solution is the amount (mass or volume) of solute present in a given amount (mass or volume) of solution.

There are various ways of expressing the concentration of a solution:

• Mass by mass percentage of a solution = \(\frac{\text{Mass of solute}}{\text{Mass of solution}}\) x 100
• Mass by volume percentage of a solution = \(\frac{\text{Mass of solute}}{\text{Volume of solution}}\) x 100
• Volume by volume percentage of a solution = \(\frac{\text{Volume of solute}}{\text{Volume of solution}}\) x 100