Calculate the number of molecules in 11.2 litres of SO2 at normal temp...
Calculation of Number of Molecules in 11.2 litres of SO2
Sulfur dioxide (SO2) is a colorless gas with a pungent odor. It is a common air pollutant and is also used as a preservative, disinfectant, and refrigerant. In this scenario, we are given the volume and type of gas, and are asked to calculate the number of molecules in the given volume.
Step 1: Convert Volume to Number of Moles
The first step is to convert the given volume to the number of moles using the ideal gas law:
PV = nRT
where
- P = pressure (in atm)
- V = volume (in L)
- n = number of moles
- R = gas constant (0.0821 L*atm/mol*K)
- T = temperature (in K)
At normal temperature and pressure (NTP), which is defined as 0°C (273 K) and 1 atm, the pressure and temperature are constant. Therefore:
PV = nRT
1 atm * 11.2 L = n * 0.0821 L*atm/mol*K * 273 K
n = 0.5017 moles of SO2
Step 2: Convert Moles to Number of Molecules
The second step is to convert the number of moles to the number of molecules using Avogadro's number:
n = N/Na
where
- n = number of moles
- N = number of molecules
- Na = Avogadro's number (6.02 x 10^23 molecules/mol)
Therefore:
N = n * Na
N = 0.5017 moles * 6.02 x 10^23 molecules/mol
N = 3.018 x 10^23 molecules of SO2
Step 3: Final Answer
Therefore, there are approximately 3.018 x 10^23 molecules of SO2 in 11.2 litres of gas at normal temperature and pressure.