Answer:
The partial pressure of oxygen in the mixture of gases is 67.5 kPa (to 3 significant figures).
Step-by-step explanation:
To find the partial pressure of oxygen in the mixture of gases, we need to use the following formula:
Partial pressure of oxygen = (moles of oxygen / total moles of gas) x total pressure
To use this formula, we need to first calculate the moles of oxygen and nitrogen in the mixture:
moles of oxygen = 48.0 g / 32.00 g/mol = 1.50 mol
moles of nitrogen = 21.0 g / 28.01 g/mol = 0.749 mol
The total moles of gas in the mixture is the sum of the moles of oxygen and nitrogen:
total moles of gas = 1.50 mol + 0.749 mol = 2.25 mol
At STP (Standard Temperature and Pressure), the total pressure is 101.3 kPa. Therefore, we can calculate the partial pressure of oxygen as:
Partial pressure of oxygen = (moles of oxygen / total moles of gas) x total pressure
Partial pressure of oxygen = (1.50 mol / 2.25 mol) x 101.3 kPa
Partial pressure of oxygen = 67.5 kPa
Therefore, the partial pressure of oxygen in the mixture of gases is 67.5 kPa (to 3 significant figures).