Chemistry- partial pressures

A sample of gas collected over water at 42 degrees C occupies a volume of one liter. The wet gas has a pressure of .986 atm. The gas is dried and the dry gas occupies 1.04 L with a pressure of 1.00 atm at 90 degrees C. Using this information, calculate the vapor pressure of water at 42 degrees C.

I was going to approach this problem by finding the pressure of the gas when dry at 42 degrees C, and then do
P[dry]= P[total] - P[water pressure]
but I realized this would get me nowhere as I didn't know the total pressure. Is there a better way to do this problem?

Calculate total mols H2O and gas @ 42o C from PV = nRT.
Calculate mols dry gas from the second set of conditions @ 90o C.
The difference in mols should be the mols H2O vapor and that put back into the PV=nRT at 42 should give P of water at 42.

  1. 👍 0
  2. 👎 0
  3. 👁 181
asked by Dave

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    A sample of gas collected over water at 42 C occupies a volume of one liter. The wet gas has a pressure of 0.986 atm. The gas is dried, and the dry gas occupies 1.04 L with a pressure of 1.00 atm at 90 C. Using this information,

    asked by Bree on October 14, 2010
  2. chemistry

    1)A sample of CO2 gas which weighs 0.85 grams has a volume of 1.30 liters when collected at 30°C. What would be the pressure of the gas sample? 2) A gas sample has an original volume of 600 ml when collected at 720 mm and 35°C.

    asked by Anonymous on April 22, 2014
  3. General Chemistry

    Answer Check... A 3.00L sample of gas was collected over water at 45 degrees Celsius. The wet gas exerts pressure of 1.50atm. When dried the sample occupies 1.80L and exerts a pressure of 1.77 atm at 80.0 degrees Celsius. What is

    asked by Kathy on September 5, 2011
  4. chemistry

    A sample of hydrogen gas was collected over water at 36 degrees celsius and 855 mmHg. The volume of the container was 6.50 L. Calculate the number of moles of H2 collected. (vapor pressure of water is 44.6 torr at 36 degrees

    asked by lavonne on October 20, 2010
  5. Chemistry

    A gas occupies a volume of 40 ml at 734.8 mm and 22* C . The gas was collected over water and the water level inside the eudiometer is the same as that outside. What is the volume of dry gas at S.T.P?

    asked by Noodle on June 19, 2011
  6. AP Chem

    a 4.22 gram sample of copper II sulfide was added to excess hydrocholoric acid with hydrogen sulfide gas being generated and collected over water. What volume of hydrogen sulfide gas would be collected at 32 degrees Celcius and

    asked by Susan Shoemaker on December 11, 2007
  7. Chemistry

    A 8.07g sample of impure Ag2O decomposes into solid silver and O2(g). If 395mL of O2(g) is collected over water at 25 degrees Celsius and 749.2 mmHg barometric pressure, then what is the percent by mass of Ag2O in the sample? The

    asked by Kim on September 30, 2017
  8. chemistry

    What volume of a oxygen at STP was collected? oxygen gas is collected over water at a temperaturee of 10 degrees C and a pressure 1.2 atm. The volume of gas plus water vapor collected is 293ml.

    asked by dee on April 6, 2016
  9. Chem hw!

    1. What pressure would be needed to compress 25.1 mL of hydrogen at 1.01 atm to 25% of its original volume? 2. If the pressure on a 1.04-L sample of gas is doubled at constant temperature, what will be the new volume of the gas?

    asked by Teisha on March 11, 2010
  10. Chem hw!

    1. What pressure would be needed to compress 25.1 mL of hydrogen at 1.01 atm to 25% of its original volume? 2. If the pressure on a 1.04-L sample of gas is doubled at constant temperature, what will be the new volume of the gas?

    asked by Teisha on March 11, 2010

More Similar Questions