Final answer:
The number of air molecules in an average room can be estimated using the volume of the room and the density of air. For a room with dimensions 5 m x 5 m x 3 m, the number of air molecules is approximately 2.0055 x 10^27 molecules.
Step-by-step explanation:
The number of air molecules in an average room can be estimated based on the volume of the room and the density of air. Let's calculate it:
The mass of one cubic meter of air is approximately 1.28 kg. Assuming the dimensions of the room are 5 m x 5 m x 3 m, the mass of air inside the room is 96 kg. Now, we need to convert it to the number of molecules:
The molar weight of air (which is a mixture of 80% nitrogen and 20% oxygen) is approximately 28.8 g/mol. Therefore, the number of moles of air in the room is equal to the mass of air divided by the molar weight: 96 kg / 0.0288 kg/mol = 3333.33 mol. Finally, we can calculate the number of molecules by multiplying the number of moles by Avogadro's number:
The number of molecules = 3333.33 mol * 6.022 x 10^23 molecules/mol = 2.0055 x 10^27 molecules.