Atmospheric pressure is simply the weight (remember Newton’s Laws) of the atmosphere pushing down
divided by the area upon which the atmosphere is pushing. The metric units of pressure are Newtons/m2
(also called a Pascal; you might also have heard of pounds per square inch [PSI], which is the English units
equivalent).
The surface (atmospheric) pressure on Venus is around 90 bars (surface pressure on the Earth is 1 bar, by
definition). Venus’ atmosphere is 96% CO2, compared to 0.035% in the Earth’s atmosphere. How much CO2
is in the Earth’s atmosphere? To simplify this calculation, you can assume that the Earth’s atmosphere is
uniformly dense and has a height of 10 km (this is the Earth’s atmospheric scale height.). The density of air
is around 1 kg/m3.
You don't need to know the Venus data to answer this problem.
The TOTAL CO2 on Earth is
(Earth area)*10^4 m*(air density)*3.5*10^-4,
assuming 3.5*10^-4 is the mass fraction of CO2. That is obsolete data, and whoever provided the problem should have stated if it was a mass or volume fraction.
Actually, 3.8^10^-4 is the current mole or volume fraction of CO2. The value of the present CO2 MASS fraction is 5.8*10^-4
You will need the Earth's surface area to complete the problem.
To find out how much CO2 is in the Earth's atmosphere, we need to calculate the mass of the Earth's atmosphere and then determine the amount of CO2 based on its percentage.
First, let's calculate the mass of the Earth's atmosphere. We know that atmospheric pressure is the weight of the atmosphere per unit area. The formula to calculate pressure is:
Pressure = Force / Area
In this case, the force is the weight of the atmosphere, and the area is the area upon which the atmosphere is pushing (which we can assume as the Earth's surface area). So, we can rewrite the formula as:
Pressure = (Weight of the Atmosphere) / (Earth's Surface Area)
Since we know that the surface pressure on Earth is 1 bar, we can convert it to Pascal by multiplying it by 100,000 (1 bar = 100,000 Pa). Now we have:
Pressure = 100,000 Pa
The weight of the atmosphere can be calculated by multiplying the atmospheric pressure by the Earth's surface area. The surface area of the Earth is approximately 5.1 x 10^14 square meters.
Weight of the Atmosphere = Pressure x Earth's Surface Area
Weight of the Atmosphere = 100,000 Pa x 5.1 x 10^14 m^2
Now, we need to convert this weight into mass. We know that density is equal to mass divided by volume. Rearranging the formula, we have:
Mass = Density x Volume
We are given the density of air as 1 kg/m^3, and we can assume the Earth's atmosphere is uniformly dense with a height of 10 km. To find the volume, we multiply the height by the surface area:
Volume = Height x Earth's Surface Area
Volume = 10,000 m x 5.1 x 10^14 m^2
Now, we can calculate the mass of the atmosphere:
Mass = Density x Volume
Mass = 1 kg/m^3 x (10,000 m x 5.1 x 10^14 m^2)
Next, we need to determine how much CO2 is in the Earth's atmosphere. We are given that Venus' atmosphere is 96% CO2. Assuming the Earth's atmosphere is uniform, we can use the same percentage to determine the amount of CO2 in the Earth's atmosphere:
Amount of CO2 = Percentage of CO2 x Mass of the Atmosphere
Amount of CO2 = 0.035% x Mass of the Atmosphere
Now, you can plug in the values and calculate the amount of CO2 in the Earth's atmosphere using the given information.