Correct Option
The correct option is 100 × (mass of the component / total mass of the solution).
Explanation
Concentration terms quantify the amount of solute present in a given quantity of solvent or solution. Mass percentage ($w/w$) is a method of expressing concentration based on the mass of the components, independent of temperature.Analysis of Options:
- 100 × (mass of the component / total mass of the solution) is Correct: The mass percentage of a component is defined as the mass of that specific component divided by the total mass of the solution, multiplied by 100.
Formula: $$\text{Mass \%} = \frac{\text{Mass of the component}}{\text{Total mass of the solution}} \times 100$$ - 100 × (mass of solute / mass of solvent) is Incorrect: This ratio compares the mass of the solute to the mass of the solvent. While useful in solubility calculations, it does not define mass percentage.
- 100 × (moles of solute / total moles of solution) is Incorrect: This formula represents mole % (mole fraction multiplied by 100), which is based on the number of moles rather than mass.
- 100 × (volume of solute / total volume of solution) is Incorrect: This defines volume percentage ($v/v$), which is typically used for liquid-liquid solutions.
Key Takeaway:
Mass percentage always relates the mass of a single component to the total mass of the solution (sum of solute and solvent masses).