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mazonaws.com instructure-uploads.s3.amazonaws.com 7. (4 pts) A sample of oxygen

ID: 915847 • Letter: M

Question

mazonaws.com instructure-uploads.s3.amazonaws.com 7. (4 pts) A sample of oxygen is collected by the downward displacement of water from an inverted ottle. The water level inside the bottle is equalized with that in the trough. Pressure is found to be 2 of 2 57mm of Hg and water temperatures 23what is the partial pressure oro21fvapor pressure of 20 at 23C is 19.8mm of Hg? 8. (4 pts) The solubility of pure oxygen in water at 20'C and 1 atm pressure.38X103 mole/liter Calculate the concentration ofoxygen at 20°C at partial pressure of 0.21 atm. 9. (5 pts) If the normal boiling point of water is 100°C and the standard heat of vaporization is 43.9 kJ/mol. Determine vapor pressure of water at 95°C

Explanation / Answer

7.

Use the Dalton’s law of partial pressures.

pO2 + pH2O = P

pO2 + 19.8 = 57.0

pO2 = 37.2 mm Hg

                       

8.

Use the Henry’s law for the solubility of gases C= const x Pgas

At 1 atm ……………..conc. is 1.38x10-3 M

At 0.21 atm ……………….X

X= 1.38x10-3 M x 0.21 atm / 1 atm = 2.90x10-4 M

9.

Use the Clausius-Clapeyron Equation:

ln (P1 / P2) = (H / R) (1/T2 - 1/T1)

Convert the temperature values in K

R = 8.314 J/mol.K

You have dH in kJ/mol, convert to J/mol.