Question

200 gram of a solution of water and sugar contains 20 g solute. What is the concentration of the solution in mass percentage?
A) $20\%$
B) $10\%$
C) $40\%$
D) $5\%$

Answer 1

The percentage by mass can be defined as the mass of the solute divided by the mass of the solution multiplied by 100. This can be represented by the following formula:

Formula used:
${\text{c}}\% = \dfrac{{{\text{mas}}{{\text{s}}_{{\text{solute}}}}}}{{{\text{mas}}{{\text{s}}_{{\text{solution}}}}}} \times 100\%$
Where,${\text{the mass of the solution }} = {\text{ mass of the solvent }} + {\text{ the mass of the solvent}}$

Complete step by step solution:
As per the given question, the mass of the solution = 200 gram
The mass of the solute in the solution = 20 g.
Hence as per the formula:
The concentration of the solution in mass percentage = ${\text{c}}\% = \dfrac{{20}}{{200}} \times 100\%$
${\text{c}}\% = 10\%$

Hence, the concentration of the sugar solution in mass percentage = $10\%$

Note:
Concentration of a solution is the measure of how much a given substance is mixed with another substance. Solutions can be either dilute or concentrated depending upon the concentration of the solute present in the solution.
Just like the expression of the concentration of the solution in the mass percentage, the solution can also be expressed as volume percentage which can be defined as the ratio of the volume of solute divided by the volume of the solution multiplied by 100 percent.
When we say that the acetic acid is $5\%$ concentrated then it means that 5 ml of acetic acid is present in 100 mL of a solution.