To calculate the number of molecules of a gas using ideal gas law and Avogadro's number.
Ozone molecules in the stratosphere absorb much of the harmful radiation from the sun. Typically, the temperature and pressure of ozone in the stratosphere are 250 K and 1.0 x 10 to the negative third atm, respectively. How many ozone molecules are present in 1.0 L of air under these conditions?