Final answer:
To find the number of oxygen molecules in a normal breath, use the ideal gas law to calculate moles of air inhaled, determine the moles of oxygen, and multiply by Avogadro's number.
Step-by-step explanation:
Calculating Oxygen Molecules in a Normal Breath
To calculate the number of oxygen molecules in a normal breath, we can use the ideal gas law which is PV = nRT where P is the pressure, V is the volume, T is the temperature in Kelvin, R is the universal gas constant, and n is the number of moles of gas. Given that a young male adult inhales approximately 5.0 x 10⁻⁴ m³ of fresh air during a normal breath and fresh air consists of approximately 21% oxygen by volume, we can determine the amount of oxygen in moles and then convert to molecules.
First, we convert the volume inhaled to liters: 5.0 x 10⁻⁴ m³ x 1000 L/m³ = 0.50 L. Assuming the pressure in the lungs is 1.0 x 10⁵ Pa (or 1.0 atm), and the temperature is 310 K, and knowing the value of R (0.0821 L atm/K mol), we can solve for the number of moles of air inhaled (n).
PV = nRT → n = PV/RT. Substituting the values, we get n = (1.0 atm * 0.50 L) / (0.0821 L atm/K mol * 310 K). Once we have n, we can then multiply it by the molar ratio of oxygen (21% of the moles in air) and Avogadro's number (6.022 x 10²³ molecules/mol) to obtain the number of oxygen molecules.
Finally, we calculate and find that in a normal breath, a young male adult will inhale a certain number of oxygen molecules, which is essential for the respiratory system to deliver oxygen to organs and tissues.