4. You have a 1.50 L oxygen (O_(2)) tank at standard temperature and pressure. How many moles of oxygen do you have?

To determine the number of moles of oxygen in a 1.50 L tank at standard temperature and pressure (STP), we can use the ideal gas law. At STP, 1 mole of any ideal gas occupies 22.4 liters.<br /><br />Given:<br />- Volume of oxygen tank = 1.50 L<br />- Standard Temperature and Pressure (STP) conditions: 0°C (273.15 K) and 1 atm pressure<br /><br />At STP, 1 mole of an ideal gas occupies 22.4 liters.<br /><br />To find the number of moles of oxygen, we can use the following relationship:<br /><br />\[ \text{Number of moles} = \frac{\text{Volume of gas}}{\text{Volume occupied by 1 mole at STP}} \]<br /><br />\[ \text{Number of moles} = \frac{1.50 \, \text{L}}{22.4 \, \text{L/mol}} \]<br /><br />\[ \text{Number of moles} \approx 0.067 \, \text{moles} \]<br /><br />Therefore, you have approximately 0.067 moles of oxygen in the 1.50 L tank at standard temperature and pressure.