Answer:
The mean free path = 2.16*10^-6 m
Explanation:
<u>Given:</u>
Pressure of gas P = 100 kPa
Temperature T = 300 K
collision cross section, σ = 2.0*10^-20 m2
Boltzmann constant, k = 1.38*10^-23 J/K
<u>To determine:</u>
The mean free path, λ
<u>Calculation:</u>
The mean free path is related to the collision cross section by the following equation:
![\lambda =\frac{1}{n\sigma }------(1)](https://tex.z-dn.net/?f=%5Clambda%20%3D%5Cfrac%7B1%7D%7Bn%5Csigma%20%7D------%281%29)
where n = number density
![n = \frac{P}{kT}-----(2)](https://tex.z-dn.net/?f=n%20%3D%20%5Cfrac%7BP%7D%7BkT%7D-----%282%29)
Substituting for P, k and T in equation (2) gives:
![n = \frac{100,000 Pa}{1.38*10^{-23} J/K*300K} =2.42*10^{25}\ m^{3}](https://tex.z-dn.net/?f=n%20%3D%20%5Cfrac%7B100%2C000%20Pa%7D%7B1.38%2A10%5E%7B-23%7D%20J%2FK%2A300K%7D%20%3D2.42%2A10%5E%7B25%7D%5C%20%20m%5E%7B3%7D)
Next, substituting for n and σ in equation (1) gives:
![\lambda =\frac{1}{2.42*10^{25}m^{-3}* .0*10^{-20}m^{2}}=2.1*10^{-6}m](https://tex.z-dn.net/?f=%5Clambda%20%3D%5Cfrac%7B1%7D%7B2.42%2A10%5E%7B25%7Dm%5E%7B-3%7D%2A%20.0%2A10%5E%7B-20%7Dm%5E%7B2%7D%7D%3D2.1%2A10%5E%7B-6%7Dm)
The characteristics of mixtures are:
a) they are made up of two of more substances
b) the two substances can be separated by physical means
c) there are two kinds of mixtures : homogenous and heterogenous
d) homogenous mixtures do not have any physicaly distinguished boundary
Answer:
B. Soap solution
Explanation:
Hardness of water refers to the degree of calcium and magnesium in the water. In other words, hard water contains excessive mineral contents. The degree of hardness of a water body can be measured using the SOAP TEST KIT.
Due to the formation of insoluble minerals, soap forms an exvessive substance in the presence of hardwater because the particles or minerals contained in the water is reacting to form something insoluble. Hence, a SOAP test kit can be used to test the hardness of water.
Answer : a) 40075.14 J/mol
Explanation :
According to the Arrhenius equation,
or,
where,
= rate constant at
= k
= rate constant at
= 10 k
= activation energy for the reaction = ?
R = gas constant = 8.314 J/mole.K
= initial temperature = 440 K
= final temperature = 550 K
Now put all the given values in this formula, we get
:
Therefore, the activation energy for the reaction is 40075.14J/mol.