Answer:
0.034 M is the molarity of sodium acetate needed.
Explanation:
The pH of the buffer solution is calculated by the Henderson-Hasselbalch equation:
![pH = pK_a + \log \frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=pH%20%3D%20pK_a%20%2B%20%5Clog%20%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
Where:
pK_a= Negative logarithm of the dissociation constant of a weak acid
![[Ac^-]](https://tex.z-dn.net/?f=%5BAc%5E-%5D)
= Concentration of the conjugate base
[HA] = Concentration of the weak acid
According to the question:
The desired pH of the buffer solution = pH = 5.27
The pKa of acetic acid = 4.74
The molarity of acetic acid solution = [HAc] = 0.01 M
The molarity of acetate ion =![[Ac^-] = ?](https://tex.z-dn.net/?f=%5BAc%5E-%5D%20%3D%20%3F)
Using Henderson-Hasselbalch equation:
![5.27= 4.74 + \log \frac{[Ac^-]}{[0.01 M]}](https://tex.z-dn.net/?f=5.27%3D%204.74%20%2B%20%5Clog%20%5Cfrac%7B%5BAc%5E-%5D%7D%7B%5B0.01%20M%5D%7D)
![[Ac^-]=0.0339 M\approx 0.034M](https://tex.z-dn.net/?f=%5BAc%5E-%5D%3D0.0339%20M%5Capprox%200.034M)
Sodium acetate dissociates into sodium ions and acetate ions when dissolved in water.
![[Ac^-]=[Na^+]=[NaAc]= 0.034M](https://tex.z-dn.net/?f=%5BAc%5E-%5D%3D%5BNa%5E%2B%5D%3D%5BNaAc%5D%3D%200.034M)
0.034 M is the molarity of sodium acetate needed.
Answer:
C2H6
Explanation:
Let us first consider the molar Masses of each gas
HBr - 80.91 g/mol
NO2 - 46.0055 g/mol
C2H6 - 30.07 g/mol
We must remember that the greater the molar mass of a gas the lesser its velocity and average kinetic energy.
Looking at the gases listed, C2H6 have the highest average kinetic energy at this temperature since it has the lowest molecular mass. This reasoning is directly derived from Graham's law of diffusion in gases.
Hence C2H6 will effuse fastest when a hole is made in the container. It also possess the greatest average kinetic energy because it has the lowest molecular mass.
Answer:
b
Explanation:
electrons lie in the orbits of the atom. they are negatively charged and they are very small in size. they have very less mass than proton. ele tron has 1/1840 mass of proton.
Answer:
0.0295M
Explanation:
As you can see, in the mixture you have KSCN and other compounds. The KSCN in solution is dissolved in K⁺ ions and SCN⁻ ions. That means initial concentration of SCN⁻ ions is the same of KSCN, 0.0800M.
You are adding 35.0mL of this solution and the total volume of the mixture is 20.0mL + 35.0mL + 40.0mL = 95.0mL.
That means you are diluting your solution 95.0mL / 35.0mL = 2.714 times.
And the concentration of SCN⁻ is:
0.0800M / 2.714 =
<h3>0.0295M </h3>
