Answer:
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<em> </em><em> </em><em> </em><em> </em><em>be</em><em>cause</em><em> </em><em>they</em><em> </em><em>are</em><em> </em><em>fully</em><em> </em><em>stable</em><em> </em><em>due</em><em> </em><em>to</em><em> </em><em>octet</em><em> </em><em>complete</em></h2>
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Answer : The acid dissociation constant Ka of the acid is, 
Explanation :
First we have to calculate the concentration of hydrogen ion.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
Given: pH = 4.06
![4.06=-\log [H^+]](https://tex.z-dn.net/?f=4.06%3D-%5Clog%20%5BH%5E%2B%5D)
![[H^+]=8.71\times 10^{-5}M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D8.71%5Ctimes%2010%5E%7B-5%7DM)
The dissociation of acid reaction is:

Initial conc. c 0 0
At eqm. c-cα cα cα
Given:
Degree of dissociation = α = 0.10 % = 0.001
![[H^+]=c\alpha](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dc%5Calpha)


The expression of dissociation constant of acid is:
![K_a=\frac{[H^+][A^-]}{[HA]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D)

Now put all the given values in this expression, we get:


Thus, the acid dissociation constant Ka of the acid is, 
For the reaction 2 K + F2 --> 2 KF,
consider K atomic wt. = 39
23.5 g of K = 0.603 moles, hence following the molar ratio of the balanced equation, 0.603 moles of potassium will use 0.3015 moles of F2. (number of moles, n = 0.3015)
Now, following the ideal gas equation, PV = nRT
P = 0.98 atm
V = unknown
n = 0.3015 moles
R = 82.057 cm^3 atm K^-1mole^-1 (unit of R chosen to match the units of other parameters; see the reference below)
T = 298 K
Solving for V,
V = (nRT)/P = (0.3015 mol * 82.057 cm^3 atm K^-1 mol^-1 * 298 K)/(0.98 atm)
solve it to get 7517.6 cm^3 as the volume of F2 = 7.5176 liters of F2 gas is needed.
2. Use the formula: volume1 * concentration 1 = volume 2 * concentration 2
where, volume 1 and concentration 1 are for solution 1 and volume 2 and solution 2 for solution 2.
Solution 1 = 12.3 M NaOH solution
Solution 2 = 1.2 M NaOH solution
<span>
Solving for volume 1, volume 1 = (12.4 L * 1.2 M)/12.3 M = 0.1366 L </span>
Answer:
1. 0.0637 moles of nitrogen.
2. The partial pressure of oxygen is 0.21 atm.
Explanation:
1. If we assume ideal behaviour, we can use the Law of ideal gases to find the moles of nitrogen, considering that air composition is mainly nitrogen (78%), oxygen (21%) and argon (1%):
2. Now, in order to find he partial pressure of oxygen we need to find the total moles of air, and then the moles of oxygen. Then, we use these results to determine the molar fraction of oxygen, to multiply it with total pressure and get the partial pressure of oxygen as follows:
As you see, the molar fraction and volume fraction are the same because of the assumption of ideal behaviour.
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