Westonci.ca is your go-to source for answers, with a community ready to provide accurate and timely information. Our Q&A platform provides quick and trustworthy answers to your questions from experienced professionals in different areas of expertise. Get immediate and reliable solutions to your questions from a community of experienced professionals on our platform.
Sagot :
Buffers are the solution that resists the change in pH. 1.39 ml of 5.90 M sodium hydroxide must be added to raise the pH to 5.75.
What is Henderson–Hasselbalch equation?
Henderson–Hasselbalch equation is used to determine the pH of the buffer by the equilibrium concentration of the acid and the conjugate base.
Moles of acetic acid are calculated as:
[tex]0.480 \times 0.0215 = 0.01032[/tex]
Moles of sodium acetate are calculated as:
[tex]0.480 \times 0.0275 = 0.0132[/tex]
The total number of moles is = 0.02352
Now, using the Henderson–Hasselbalch equation:
[tex]\rm pH = \rm pKa + log \dfrac{[Acetate]}{[Acetic\; acid]}[/tex]
Given,
pH = 5.75
pKa = 4.74
Substituting values in the above equation:
[tex]\begin{aligned} 5.75 &= 4.74 +\rm log \rm \dfrac{[Acetate]}{[Acetic\; acid]}\\\\10.2329 &= \rm \dfrac{[Acetate]}{[Acetic\; acid]}\end{aligned}[/tex]
Solving further:
[tex]\begin{aligned} 10.2329 &= 0.02352 - \rm \dfrac{[Acetic\; acid]}{[Acetic\; acid]}\\\\11.2329\; \rm [Acetic \; acid] &= 0.02352 \\\\&= 0.002093\end{aligned}[/tex]
Moles of acetate is calculated as:
0.02352 moles - 0.002093 moles = 0.021427 moles
Initial moles of acetate were 0.0132, added moles of acetate by the addition of the sodium hydroxide resulted in, 0.021427 - 0.0132 = 0.00822 moles of sodium hydroxide.
Volume is calculated as:
[tex]0.00822 \;\rm moles \times \dfrac{1\;\rm L}{5.90\;\rm M} = 0.00139 L[/tex]
Therefore, 1.39 mL of 5.90M of sodium hydroxide is added.
Learn more about Henderson–Hasselbalch equation here:
https://brainly.com/question/19755735
#SPJ4
We hope this information was helpful. Feel free to return anytime for more answers to your questions and concerns. Your visit means a lot to us. Don't hesitate to return for more reliable answers to any questions you may have. Westonci.ca is your go-to source for reliable answers. Return soon for more expert insights.
