In which of one the following all the concentration terms are independent of temperature?

mole fraction, mass fraction, molality

The correct answer is Option (4) → mole fraction, mass fraction, molality

Let’s analyze each concentration term:

1. Molarity (M) – moles of solute per liter of solution → depends on volume, which changes with temperature → temperature dependent
2. Molality (m) – moles of solute per kg of solvent → depends on mass, independent of temperature
3. Mole fraction (x) – ratio of moles → depends on number of moles, independent of temperature
4. Mass fraction (w) – ratio of masses → independent of temperature
5. ppm – parts per million by mass or volume → mass-based ppm is independent, volume-based is temperature dependent

 Terms independent of temperature:

• Molality
• Mole fraction
• Mass fraction 
  Hence, OPTION 4 IS CORRECT