वाष्प दाब और क्वथनांक

तापमान के साथ वाष्प दाब के परिवर्तन को मापना

Gas Laws Advanced (University) 45 मिनट ~$12.00

उद्देश्य

विभिन्न तापमानों पर पानी का वाष्प दाब मापें और क्लॉसियस-क्लेपेयरॉन समीकरण को सत्यापित करें।

पृष्ठभूमि

The vapor pressure of a liquid increases exponentially with temperature. By measuring the temperature at which water boils under different reduced pressures (or measuring vapor pressure at different temperatures), the enthalpy of vaporization can be determined from the Clausius-Clapeyron equation.

सुरक्षा चेतावनियाँ

  • Handle vacuum apparatus carefully — implosion risk with glass
  • Hot water can cause burns
  • Use proper vacuum-rated glassware only

आवश्यक PPE

goggles lab_coat

सामग्री

  • Distilled water (200 mL)
  • Ice (500 g)
    For cold water bath

उपकरण

Round-bottom flask (500 mL) Vacuum pump or syringe Pressure gauge or manometer Thermometer Hot plate Rubber tubing Graph paper

प्रक्रिया

1

Set up the flask with water, thermometer, and pressure gauge. Connect to the vacuum pump.

5 मिनट Use vacuum-rated glassware only
2

Heat the water to 80°C. Record the temperature and vapor pressure.

5 मिनट
3

Reduce pressure with the vacuum pump. Note the temperature at which boiling begins.

5 मिनट
4

Record at least 8 temperature-pressure data points from 40°C to 100°C.

15 मिनट
5

Plot ln(P) vs 1/T(K). The slope = -ΔHvap/R.

10 मिनट
6

Calculate ΔHvap from the slope. Compare with the literature value of 40.7 kJ/mol.

5 मिनट

अपेक्षित परिणाम

The ln(P) vs 1/T plot should be linear with a negative slope. The calculated ΔHvap should be approximately 40-44 kJ/mol, close to the accepted value of 40.7 kJ/mol for water.

सफाई

Release vacuum slowly. Turn off heater. Drain water and dry apparatus.

Frequently Asked Questions

What is the objective of वाष्प दाब और क्वथनांक?
विभिन्न तापमानों पर पानी का वाष्प दाब मापें और क्लॉसियस-क्लेपेयरॉन समीकरण को सत्यापित करें।
How difficult is वाष्प दाब और क्वथनांक?
This experiment is rated as Advanced (University). It takes approximately 45 minutes to complete.
What safety precautions are needed for वाष्प दाब और क्वथनांक?
Key safety precautions include: Handle vacuum apparatus carefully — implosion risk with glass; Hot water can cause burns; Use proper vacuum-rated glassware only.
What materials are needed for वाष्प दाब और क्वथनांक?
The main materials required are: Distilled water, Ice.
What results should I expect from वाष्प दाब और क्वथनांक?
The ln(P) vs 1/T plot should be linear with a negative slope. The calculated ΔHvap should be approximately 40-44 kJ/mol, close to the accepted value of 40.7 kJ/mol for water.