For a dilute solut ion, Raoult’s law states that:a)The lowering ...
According to Raoult's law, for dilute solutions containing non volatile solute, the relative lowering of vapor pressure, Δp/po is equal to the mole fraction of solute, X2. * The lowering of vapor pressure is proportional to the mole fraction of solute or inversely related to mole fraction of solvent.
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For a dilute solut ion, Raoult’s law states that:a)The lowering ...
Explanation:
Introduction to Raoult's Law:
Raoult's Law, formulated by French chemist François-Marie Raoult in 1887, relates the vapor pressure of an ideal solution to the mole fraction of solute in the solution. It is applicable to dilute solutions, where the solute concentration is relatively low compared to the solvent concentration.
Statement of Raoult's Law:
According to Raoult's Law, the relative lowering of vapor pressure of a solvent in a dilute solution is directly proportional to the mole fraction of solute in the solution. Mathematically, it can be expressed as:
∆P/P₀ = x₂
Where:
∆P = lowering of vapor pressure of the solvent
P₀ = vapor pressure of the pure solvent
x₂ = mole fraction of solute
Explanation of the Correct Answer (Option B):
The correct answer, option B, states that the relative lowering of vapor pressure is equal to the mole fraction of solute. This means that the decrease in vapor pressure of the solvent in a dilute solution is directly proportional to the amount of solute present.
Elaboration:
- When a non-volatile solute is added to a solvent, it occupies some of the space on the surface of the solvent, leading to a decrease in the number of solvent molecules escaping into the vapor phase.
- Consequently, the vapor pressure of the solvent decreases, as fewer solvent molecules are available to escape into the gas phase.
- The decrease in vapor pressure is directly proportional to the mole fraction of the solute, meaning that the more solute molecules present in the solution, the greater the lowering of vapor pressure.
Importance of Raoult's Law:
Raoult's Law is essential for understanding colligative properties of solutions, such as boiling point elevation and freezing point depression. It provides a quantitative relationship between the vapor pressure of a solvent in a solution and the mole fraction of the solute.
Limitations of Raoult's Law:
It is important to note that Raoult's Law is only applicable to ideal solutions, where the interactions between the solute and solvent molecules are similar to those between solvent-solvent and solute-solute molecules. In reality, many solutions deviate from ideal behavior, especially at higher solute concentrations or in the presence of strong intermolecular forces.
Conclusion:
In summary, Raoult's Law states that the relative lowering of vapor pressure in a dilute solution is directly proportional to the mole fraction of the solute. This relationship is crucial for understanding the behavior of solutions and their colligative properties.
For a dilute solut ion, Raoult’s law states that:a)The lowering ...
Correct answer is option 'B'