a quantity of oxygen occupies a volume of 19.2L at STP. How many moles of oxygen are present?
1 mole occupies 22.4L at STP.
To determine the number of moles of oxygen present, you 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.
At STP (Standard Temperature and Pressure), the pressure is defined to be 1 atmosphere (atm), and the temperature is 273.15 Kelvin (K).
Given:
Pressure (P) = 1 atm
Volume (V) = 19.2 L
Temperature (T) = 273.15 K
To solve for the number of moles (n), rearrange the ideal gas law equation as follows:
n = PV / RT
Substituting the given values:
n = (1 atm) * (19.2 L) / [(0.0821 L·atm/mol·K) * (273.15 K)]
Now, we can simplify the equation:
n = 19.2 / (0.0821 * 273.15)
n ≈ 0.741 moles
Therefore, there are approximately 0.741 moles of oxygen present in a volume of 19.2L at STP.