dr. bob

Use the data in Table 5.4 to calculate the partial pressure of He in dry air assuming that the total pressure is 1.0 atm. Assuming a temperature of 21°C, calculate the number of He atoms per cubic centimeter.
atoms/cm3



.00000524 - atmospheric composition of airnear sea level for He(info from table)

not a clue

  1. 👍 0
  2. 👎 0
  3. 👁 156
asked by mel
  1. What are the units here (for the composition of Helium at sea level)? percent? mols?

    1. 👍 0
    2. 👎 0
  2. moles

    1. 👍 0
    2. 👎 0
    posted by mel
  3. In the Earth's atmosphere, the concentration of helium by volume (also called the "mole fraction") is 5.2 parts per million. At 1 atm and 21C, the molar density of air is
    1 mole /24,100 cm^3. Multiple that by the mole fraction and Avogadro's number for the number of He atoms per cm^3.
    I get 1.3*10^13.

    1. 👍 0
    2. 👎 0
    posted by drwls

Respond to this Question

First Name

Your Response

Similar Questions

  1. chemistry

    on a particularly hot 30 degrees C day near the seashore the partial pressure of water vapor in the air is .0303atm. given that the atmospheric pressure is 1 atm and the composition of dry air is 78% N, 21% O and 1%Ar, what is the

    asked by Stacey on October 7, 2010
  2. Chemistry

    on a particularly hot 30 degrees C day near the seashore the partial pressure of water vapor in the air is .0303atm. given that the atmospheric pressure is 1 atm and the composition of dry air is 78% N, 21% O and 1%Ar, what is the

    asked by Missy* on October 7, 2010
  3. Chemistry

    Three of the primary components of air are carbon dioxide, nitrogen, and oxygen. In a sample containing a mixutre of only these gases at exactly one atmosphere pressure, the partial pressure of carbon dixoide and nitrogen are

    asked by Chopsticks on March 25, 2009
  4. Chemistry

    This is a question on Non-standard states. Calculate ¥ÄG605 for the following reaction under the given conditions. Use data obtained from the table below and assume that ¥ÄHo and ¥ÄSo do not vary with temperature. C2H4(g) +

    asked by Sally on February 2, 2007
  5. College Chemistry

    When determining the vapor pressure of water, the bubble volume is 1.2mL at 5 degrees celsius. -How many moles of dry air were in the bubble? (assume 1 atm) -If the bubble volume is 8.6mL at 75 degrees celsius, what is the partial

    asked by Abbey on April 18, 2013
  6. College Chemistry

    When determining the vapor pressure of water, the bubble volume is 1.2mL at 5 degrees celsius. -How many moles of dry air were in the bubble? (assume 1 atm) -If the bubble volume is 8.6mL at 75 degrees celsius, what is the partial

    asked by Abbey on April 18, 2013
  7. College Chemistry

    When determining the vapor pressure of water, the bubble volume is 1.2mL at 5 degrees celsius. -How many moles of dry air were in the bubble? (assume 1 atm) -If the bubble volume is 8.6mL at 75 degrees celsius, what is the partial

    asked by Abbey on April 18, 2013
  8. chemistry

    A 1.00-L sample of dry air at 25 °C contains 0.0319 mol N2, 0.00856 mol O2, ... The main components of dry air, by volume, are N2, 78.08%; O2, 20.95%; Ar, ... by volume, of the following main gaseous components: N2, 74.1%; O2,

    asked by Kate on April 19, 2011
  9. Thermodynamics

    Heyy, Okay so I have a question that I'm trying to figure out how to do and I'm really lost, I was hoping somebody might be able to give me a hand. Thanks in advance. The question in general is, I know that the vapour pressure of

    asked by Tracy on September 16, 2007
  10. chemistry 106

    Dry air near sea level has the following composition by volume: N2, 78.08 percent; O2, 20.94 percent; Ar, 0.93 percent; CO2, 0.05 percent. The atmospheric pressure is 1.00 atm. (Hint: Since volume is proportional to the number of

    asked by Tanisha on March 1, 2010

More Similar Questions