Answer:
10.88 g
Explanation:
We have:
[CH₃COOH] = 0.10 M
pH = 5.25
Ka = 1.80x10⁻⁵
V = 250.0 mL = 0.250 L
The pH of the buffer solution is:
![pH = pKa + log(\frac{[CH_{3}COONa*3H_{2}O]}{[CH_{3}COOH]})](https://tex.z-dn.net/?f=%20pH%20%3D%20pKa%20%2B%20log%28%5Cfrac%7B%5BCH_%7B3%7DCOONa%2A3H_%7B2%7DO%5D%7D%7B%5BCH_%7B3%7DCOOH%5D%7D%29%20)
(1)
By solving equation (1) for [CH₃COONa*3H₂O] we have:
![log [CH_{3}COONa*3H_{2}O] = pH - pKa + log [CH_{3}COOH]](https://tex.z-dn.net/?f=%20log%20%5BCH_%7B3%7DCOONa%2A3H_%7B2%7DO%5D%20%3D%20pH%20-%20pKa%20%2B%20log%20%5BCH_%7B3%7DCOOH%5D%20)
![log [CH_{3}COONa*3H_{2}O] = 5.25 - (-log(1.80 \cdot 10^{-5})) + log (0.10) = -0.495](https://tex.z-dn.net/?f=%20log%20%5BCH_%7B3%7DCOONa%2A3H_%7B2%7DO%5D%20%3D%205.25%20-%20%28-log%281.80%20%5Ccdot%2010%5E%7B-5%7D%29%29%20%2B%20log%20%280.10%29%20%3D%20-0.495%20)
![[CH_{3}COONa*3H_{2}O] = 10^{-0.495} = 0.32 M](https://tex.z-dn.net/?f=%5BCH_%7B3%7DCOONa%2A3H_%7B2%7DO%5D%20%3D%2010%5E%7B-0.495%7D%20%3D%200.32%20M)
Hence, the mass of the sodium acetate tri-hydrate is:
![m = moles*M = [CH_{3}COONa*3H_{2}O]*V*M = 0.32 mol/L*0.250 L*136 g/mol = 10.88 g](https://tex.z-dn.net/?f=m%20%3D%20moles%2AM%20%3D%20%5BCH_%7B3%7DCOONa%2A3H_%7B2%7DO%5D%2AV%2AM%20%3D%200.32%20mol%2FL%2A0.250%20L%2A136%20g%2Fmol%20%3D%2010.88%20g)
Therefore, the number of grams of CH₃COONa*3H₂O needed to make an acetic acid/sodium acetate tri-hydrate buffer solution is 10.88 g.
I hope it helps you!
Answer:
dark coloured rock with coarse grains in parallel layers
Explanation:
Longer wavelength means frequency is lower, thus pitch is lower
Answer: I think you should go for someone as long as you like them for who they are and not just for their looks. In my opinion, someone's personality is more important than how they look.
Hope this helps! :)
Explanation:
When the concentration of H+ and OH- are equal, the pH = 7
Since together, the -log [H+] + -log [OH-] must equal 14 for all aqueous systems.
