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Calculate the mass of a non volatile solute ( molecular mass = 40) ,which. should be dissolved in 114g octane to reduce it's vapour pressure to 80%?
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Introduction
To find the mass of a non-volatile solute needed to decrease the vapor pressure of octane, we will apply Raoult's Law.
Given Data
- Molecular mass of solute = 40 g/mol
- Mass of octane (solvent) = 114 g
- Vapor pressure reduction = 80%
Calculating Vapor Pressure
- The initial vapor pressure of pure octane = P0
- Reduced vapor pressure = 80% of P0 = 0.8 P0
Applying Raoult's Law
According to Raoult's Law:
- P_solution = X_solvent * P0
Where:
- P_solution is the vapor pressure of the solution
- X_solvent is the mole fraction of the solvent
Since we know the reduced vapor pressure:
- 0.8 P0 = X_solvent * P0
- Therefore, X_solvent = 0.8
Finding Mole Fraction of Solute
- Mole fraction of solute (X_solute) = 1 - X_solvent
- X_solute = 1 - 0.8 = 0.2
Calculating Moles of Octane
- Molar mass of octane (C8H18) = 114 g/mol
- Moles of octane = 114 g / 114 g/mol = 1 mol
Finding Moles of Solute
Using the mole fraction:
- X_solute = moles of solute / (moles of solute + moles of solvent)
- 0.2 = n / (n + 1)
- Solving gives n (moles of solute) = 0.2 mol
Calculating Mass of Solute
- Mass of solute = moles * molar mass = 0.2 mol * 40 g/mol = 8 g
Conclusion
To reduce the vapor pressure of 114 g of octane to 80%, 8 g of the non-volatile solute should be dissolved.
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Calculate the mass of a non volatile solute ( molecular mass = 40) ,which. should be dissolved in 114g octane to reduce it's vapour pressure to 80%?
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Calculate the mass of a non volatile solute ( molecular mass = 40) ,which. should be dissolved in 114g octane to reduce it's vapour pressure to 80%? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about Calculate the mass of a non volatile solute ( molecular mass = 40) ,which. should be dissolved in 114g octane to reduce it's vapour pressure to 80%? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Calculate the mass of a non volatile solute ( molecular mass = 40) ,which. should be dissolved in 114g octane to reduce it's vapour pressure to 80%?.
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