Freon-12,CF₂Cl₂,which has been widely used in air conditioning systems,is considered a threat to the ozone layer in the stratosphere.Calculate the root-mean-square velocity of Freon-12 molecules in the lower stratosphere where the temperature is -65°C.

Question

Quizplus · Accepted Answer

We can use the root-mean-square velocity formula: 
v(rms) = √(3kT/m) 
where k is Boltzmann's constant, T is the temperature in Kelvin, and m is the mass of the molecule.

First, we need to convert the temperature from Celsius to Kelvin: 
T = -65°C + 273.15 = 208.15 K

The mass of Freon-12 is approximately 120.91 g/mol or 0.12091 kg/mol. We can convert this to kg/particle by dividing by Avogadro's number (6.022 x 10^23 particles/mol): 
m = 0.12091 kg/mol / 6.022 x 10^23 particles/mol 
m = 2.01 x 10^-25 kg/particle

Now we can substitute the values into the formula: 
v(rms) = √(3kT/m) 
v(rms) = √(3 x 1.38 x 10^-23 J/K x 208.15 K / 2.01 x 10^-25 kg/particle) 
v(rms) = 210 m/s

Therefore, the root-mean-square velocity of Freon-12 molecules in the lower stratosphere at -65°C is approximately 210 m/s. The answer is (C).

Freon-12,CF2Cl2,which Has Been Widely Used in Air Conditioning Systems,is Considered ×\times×

Freon-12,CF₂Cl₂,which Has Been Widely Used in Air Conditioning Systems,is Considered $\times$