Respuesta :
Answer:
E. 0.497
Explanation:
Graham's law of diffusion or effusion states that the rate of diffusion or effusion is inversely proportional to the square root of the molecular mass.
k=r√m
1=HF, 2=HBr
Molar mass of HF=20. Molar mass of HBr=80.91
r1√20=r2√80.91
r1/r2=4.472/8.994
r1/r2=0.497
r1√m1=r2√m2
Answer: Option (B) is the correct answer.
Explanation:
According to the Graham's law, rate of effusion of a gas is inversely proportional to the square root of molar mass of the gas.
Mathematically, Rate of effusion = [tex]\frac{1}{\sqrt{M}}[/tex]
where, M = molar mass of gas
As molar mass of HF is 20.01 g/mol and molar mass of HBr is 80.91 g/mol. Therefore, calculate the ratio of rate of effusion of HF to the rate of effusion of HBr as follows.
[tex]\frac{R_{HF}}{R_{HBr}}[/tex] = [tex]\sqrt{\frac{80.91 g/mol}{20.01 g/mol}}[/tex]
= [tex]\sqrt{4.04}[/tex]
= 2.009
= 2.01 (approx)
Thus, we can conclude that ratio of the rate of effusion of HF to the rate of effusion of HBr is 2.01.
