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

    1. 👍
    2. 👎
  2. moles

    1. 👍
    2. 👎
  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. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    1. A small piece of zinc reacts with dilute HCl to form H2, which is collected over water at 16°C into a large flask. The total pressure is adjusted to barometric pressure (752 torr), and the volume is 1538 mL. Use Table 5.2 to

  2. Chemistry

    Three gases (8.00 g of methane, CH4, 18.0 g of ethane, C2H6, and an unknown amount of propane, C3H8) were added to the same 10.0-L container. At 23.0 ∘C, the total pressure in the container is 4.40 atm . Calculate the partial

  3. chemistry

    The mole fraction of nitrogen in air is 0.7808. calculate the partial pressure of N2 in air when the atmospheric pressure is 760 torr?

  4. chemistry

    1-Dinitrogen tetroxide (N2O4) dissociates according to the equation: N2O4 ⇌ 2NO2 An equilibrium reaction mixture at 25 ºC was found to have the partial pressure of N2O4 as 72 kPa whilst the partial pressure of nitrogen dioxide

  1. Chemistry

    Consider the following reaction: CO(g)+H2O(g)⇌CO2(g)+H2(g) Kp=0.0611 at 2000 K A reaction mixture initially contains a CO partial pressure of 1380 torr and a H2O partial pressure of 1730 torr at 2000 K. Calculate the equilibrium

  2. Chemistry

    At a total atmospheric pressure of 1.00 atm, the partial pressure of CO2 in air is approximately 4.0×10−4 atm. If at 20 ∘C and a partial pressure of 760 mmHg, the solubility of CO2 in water is 0.169 g/100mL, what is the

  3. Chemistry

    On a clear day at sea level, the partial pressure of N2 in air is 0.78 atm at 25 degres C. Under these conditions, the concentration of N2 in water is 5.3 x 10^-4 M. What is the partial pressure of N2 when the concentration in

  4. Chemistry-Please help

    Air is about 78.0% nitrogen molecules and 21.0% oxygen molecules. Several other gases make up the remaining 1% of air molecules. A)What is the partial pressure of nitrogen in air at atmospheric pressure (1 atm)? Assume ideal

  1. Chemistry

    Nitric oxide (NO) reacts with molecular oxygen as follows: 2NO(g) + O2(g) ¨ 2NO2(g) Initially NO and O2 are separated as shown below. When the valve is opened, the reaction quickly goes to completion. Determine what gases

  2. chem 102

    Use Henry's law and the solubilities given below to calculate the total volume of nitrogen and oxygen gas that should bubble out of 1.1L of water upon warming from 25 ∘C to 50 ∘C. Assume that the water is initially saturated

  3. chemistry

    A piece of dry ice (solid carbon dioxide) with a mass of 5.40 g is placed in a 10.0 L vessel? that already contains air at 715 torr and 25 degrees C. After the carbon dioxide has totally vaporized, what is the partial pressure of

  4. chemistry

    So the question I have is: Calculate the pressure of dry hydrogen collected. (Use the water temperature). And the evidence that we obtained was: Length of magnesium 3.8Cm Mass of 1 m of magnesium 1.254g Volume of hydrogen

You can view more similar questions or ask a new question.