Respuesta :
This question is incomplete, here is the complete question:
Imagine that you have been assigned 5 substances for which you will observe the rate of diffusion. The only information that you have about your materials is the molecular weight of each substance, listed below:
Substance #1: 212 mg
Substance #2: 1918 mg
Substance #3: 50 mg
Substance #4: 4 mg
Substance #5: 700 mg
If the substances are allowed to diffuse for one hour, what can you predict about the rate of diffusion?
Answer:
Substance #4 will diffuse faster with a relative molecular weight of 4mg
Substance #3 with weight of 50mg will diffuse next
Substance #1 with 212mg will follow
Substance #5 and then
Substance #2
Therefore;
#4, #3, #1, #5, #2
Explanation:
Law of diffusion states that, rate of diffusion is inversely proportional to the square root of its density, at constant temperature and pressure.
Mathematically, it can be written as;
R = k/√d
Where, k is a constant.
Also, it should be noted that, when comparing the rate of diffusion of two gases, the equation will be
R1/R2 = √d2/√d1
There is a relationship between density of a gas and it's relative molecular weight. The density of a gas, d, is directly proportional to its relative molecular weight.
Mathematically,
R1/R2 = √M2/√M1
Since, rate is the reciprocal of time, R = 1/t, substituting R1 = 1/t1 and R2 = 1/t2, we get;
R1/R2 = t2/t1 = √M2/√M1.
In order to estimate their respective rate of diffusion, find the square root of their respective molecular weight and to least will diffuse faster.
Answer:
Imagine that you have been assigned 5 substances for which you will observe the rate of diffusion. The only information that you have about your materials is the molecular weight of each substance, listed below:
Substance #1: 212 mg
Substance #2: 1918 mg
Substance #3: 50 mg
Substance #4: 4 mg
Substance #5: 700 mg
If the substances are allowed to diffuse for one hour, what can you predict about the rate of diffusion?
The answer to the question is
That the lighter substances will diffuse more than the substances with larger molecular masses
That is Substance #4: 4 mg which has the least molecular mass will diffuse the most
Explanation:
Graham's law of diffusion of a gas states that the rate of diffusion of a gas is inversely proportional to the square root of its molecular mass
That is
[tex]\frac{Rate 1}{Rate 2} =\sqrt{\frac{Mass 2}{Mass 1} }[/tex]
i.e. r ∝ √(Molar Mass) and r × √(Molar Mass) = constant
Where r = Diffusion rate
Considering the listed gases we have
(Rate of subsatane 1)/ (Rte of substance 2) =
[tex]\frac{Rate of substance 1}{Rate of substance 2} =\sqrt{\frac{Molar Mass 2}{Molar Mass 1} }[/tex] =
[tex]\frac{Rate 1}{Rate 2} =\sqrt{\frac{1918 mg}{212 mg} } = 3.0[/tex] ≅ 3.0
Hence Substance 1 diffuses faster than substance 2
The same can be said of the rest where the rate of diffusion is inversely proportional to the molar mass
And so
R1:R2 = 3.00
R1:R3 = 0.48
R1:R4 = 0.14
R1:R5 = 1.82
Therefore the rate of diffusion of the gases in incresing order is
R2 → R5 → R1 → R3 → R4
Which is the same order as the decreasing order of their molar mass
Substance #2: 1918 mg , Substance #5: 700 mg, Substance #1: 212 mg, Substance #3: 50 mg , Substance #4: 4 mg
