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