Dr BOB can you explain this to me. I am so struggling with this subject.
during a typical breathing cycle the CO2 concentration in the expired air rises to a peak of 4.6% by volume. Calculate the partial pressure of the CO2 at this point, assuming 1 bar of pressure. what is the molarity of the CO2 in the air at this point, assuming body temp is 37 degreesC.
any help will do?
To answer your question, we will use the ideal gas law and Henry's Law. Here's how you can calculate the partial pressure and molarity of CO2 in the expired air:
1. Calculate the partial pressure of CO2:
To find the partial pressure of CO2, we can use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
Given:
CO2 concentration in the expired air (by volume) = 4.6%
Pressure (P) = 1 bar
Volume (V) = unknown
Temperature (T) = 37 degrees Celsius
First, convert the temperature to Kelvin:
T(K) = T(C) + 273.15
T(K) = 37 + 273.15 = 310.15 K
Next, convert the CO2 concentration to a decimal value:
CO2 concentration = 4.6% = 0.046
Now, rearrange the ideal gas law equation to solve for the number of moles (n):
n = PV / RT
Substitute the given values into the equation:
n = (1 bar) x V / (0.0831 L·bar/mol·K) x (310.15 K)
To solve for V, we need to know the exact volume of expired air during a breathing cycle.
2. Calculate the molarity of CO2:
To calculate the molarity, we need the number of moles of CO2 dissolved in a known volume of water. Unfortunately, your question does not provide enough information about how the CO2 is dissolved in the air.
If you have information about the amount of dissolved CO2 in a known volume of water, you can calculate the molarity using the formula:
Molarity (M) = moles of solute / volume of solution in liters
However, without this specific information, we cannot calculate the molarity.
In summary, to find the partial pressure of CO2, you can use the ideal gas law equation. However, without additional information about how CO2 is dissolved in a known volume of water, the molarity cannot be determined.