# The density of air #20# #km# above Earths surface is #92# #g##/##m^3.# The pressure of the atmosphere is #42# #mm# #Hg#, and the temperature is #-63# #°C#. What is the average molar mass of the atmosphere at this altitude?

##
If the atmosphere at this altitude consists of only #O_2# and #N_2# , what is the mole fraction of each gas?

If the atmosphere at this altitude consists of only

Here's what I got.

The idea behind this is that you should begin by solving the ideal gas law equation in its standard form.

and make an effort to adjust it by adding molar mass and density.

Since mass per unit of mole is the definition of molar mass, you can write the number of moles of a substance by using both its mass and molar mass.

Enter this into the formula color(purple)((1)) to obtain

Let's now concentrate on density, which is defined as mass per volume unit.

You'll get this

The weighted average of the molar masses of the constituent gases of air is now used to determine the average molar mass of air.

More precisely, according to its mole fraction in the mixture, each gas will contribute a certain amount to the average molar mass.

The nitrogen gas and oxygen gas molar masses are

Apply these two formulas to obtain

This indicates that you've

You must now round these responses to the nearest two sig figs, or the total number of sig figs you have for the supplied values.

By signing up, you agree to our Terms of Service and Privacy Policy

The average molar mass of the atmosphere at this altitude is approximately 29.8 g/mol.

By signing up, you agree to our Terms of Service and Privacy Policy

To find the average molar mass of the atmosphere at this altitude, we can use the ideal gas law equation:

PV = nRT

Where: P = pressure (in atmospheres) V = volume (in liters) n = number of moles R = ideal gas constant (0.0821 L.atm/mol.K) T = temperature (in Kelvin)

We need to rearrange this equation to solve for the number of moles (n):

n = PV / RT

First, we need to convert pressure from mm Hg to atm:

1 atm = 760 mm Hg

So, 42 mm Hg = 42 / 760 atm

Now, let's convert the temperature from Celsius to Kelvin:

Temperature in Kelvin = Temperature in Celsius + 273.15

So, -63 °C = -63 + 273.15 K

Now, we can plug in the values into the equation:

n = (42 / 760) * V / (0.0821 * (-63 + 273.15))

The volume (V) is not given, but since we are dealing with the density of air, we can consider a volume of 1 m^3 for simplicity.

n = (42 / 760) * 1 / (0.0821 * (-63 + 273.15))

Now, we can calculate the number of moles (n).

n ≈ 0.002836 moles

Now, we can use the definition of molar mass:

Molar mass (M) = mass / number of moles

Given that the density of air is 92 g/m^3, the mass of 1 m^3 of air is 92 g.

So, molar mass (M) = 92 g / 0.002836 moles

M ≈ 32458 g/mol

Thus, the average molar mass of the atmosphere at this altitude is approximately 32.458 kg/mol.

By signing up, you agree to our Terms of Service and Privacy Policy

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

- What is the volume of 36.8 g of carbon monoxide at STP?
- If oxygen is removed from a sample of air as iron rusts, what happens to the partial pressure of oxygen in the air?
- How would you calculate the partial pressure of CO2, given an atmospheric pressure of 760 mm Hg and a 0.04% concentration?
- How does Boyle's law relate to a bicycle pump?
- How do you convert 350.0 mL at 740.0 mm of Hg to its new volume at standard pressure?

- 98% accuracy study help
- Covers math, physics, chemistry, biology, and more
- Step-by-step, in-depth guides
- Readily available 24/7