\begin{tabular}{|l|l|}
\hline
Ideal gas law & [tex]$PV=nRT$[/tex] \\
\hline
Ideal gas constant & [tex]$R=8.314 \frac{ L \cdot kPa }{ mol \cdot K }$[/tex] \\
& or \\
& [tex]$R=0.0821 \frac{ L \cdot atm }{ mol \cdot K }$[/tex] \\
\hline
Standard atmospheric pressure & [tex]$1 atm=101.3 kPa$[/tex] \\
\hline
Celsius to Kelvin conversion & [tex]$K = { }^{\circ} C + 273.15$[/tex] \\
\hline
\end{tabular}

Select the correct answer.

A human lung at maximum capacity has a volume of 3.0 liters. If the partial pressure of oxygen in the air is 21.1 kilopascals and the air temperature is 295 K, how many moles of oxygen are in the lung?

A. [tex]$\quad 0.026 \, mol$[/tex]

B. [tex]$\quad 0.12 \, mol$[/tex]

C. [tex]$\quad 2.6 \, mol$[/tex]

D. [tex]$\quad 13 \, mol$[/tex]



Answer :

To solve this problem, we will use the Ideal Gas Law, which is stated as:

[tex]\[ PV = nRT \][/tex]

Where:
- [tex]\( P \)[/tex] is the pressure of the gas,
- [tex]\( V \)[/tex] is the volume of the gas,
- [tex]\( n \)[/tex] is the number of moles of the gas,
- [tex]\( R \)[/tex] is the ideal gas constant,
- [tex]\( T \)[/tex] is the temperature of the gas in Kelvin.

We are given the following data:
- Volume of the lung, [tex]\( V = 3.0 \)[/tex] liters
- Partial pressure of oxygen, [tex]\( P = 21.1 \)[/tex] kilopascals
- Temperature, [tex]\( T = 295 \)[/tex] Kelvin
- Ideal gas constant, [tex]\( R = 8.314 \frac{L \cdot kPa}{mol \cdot K} \)[/tex]

We need to find the number of moles of oxygen, [tex]\( n \)[/tex]. We can rearrange the Ideal Gas Law to solve for [tex]\( n \)[/tex]:

[tex]\[ n = \frac{PV}{RT} \][/tex]

Substitute the provided values into the equation:

[tex]\[ n = \frac{(21.1 \, kPa) \cdot (3.0 \, L)}{(8.314 \, \frac{L \cdot kPa}{mol \cdot K}) \cdot (295 \, K)} \][/tex]

Now, calculate the number of moles:

[tex]\[ n \approx 0.0258 \][/tex]

Therefore, the number of moles of oxygen in the lung is approximately [tex]\( 0.0258 \)[/tex] moles. Given the options, the closest value to our calculated result is:

A. [tex]\( 0.026 \)[/tex] moles

So, the correct answer is:
[tex]\[ \boxed{0.026 \, mol} \][/tex]