Solving pH Changes in Buffer Initial pH 4.45

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In summary: What are the known conditions?In summary, the problem being discussed involves adding different amounts of NaOH to a solution and finding the resulting pH. However, without knowing the buffer concentration and type, it is not possible to accurately calculate the pH when 1.00 mL NaOH is added. When 0.0 mL NaOH is added, the pH does not change, but it is possible this is a typo in the problem description. More information is needed to solve this problem accurately.
  • #1
lha08
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Homework Statement


If the initial buffer pH is 4.45, what is the pH when 1.00 mL NaOH is added to 35 mL of water?
Also, if 0.0 mL NaOH is added, what is the pH then?

Homework Equations





The Attempt at a Solution


I have no idea how to do this...all i can think of is to change the pH to [H+] and add the moles of that with the moles formed by NaOH (i tried using OH and using its pOH and finding the pH and converting back to H+) but when i add them together and divide by the total volume it's wrong...supposedly the measured pH for the addition of 1.00 ml is 11.14 and for the 0.00 added it's 4.73..thanks
 
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  • #2
lha08 said:

Homework Statement


If the initial buffer pH is 4.45, what is the pH when 1.00 mL NaOH is added to 35 mL of water?

You are not given buffer concentration, nor buffer type? Then there is no answer to this question.

Also, if 0.0 mL NaOH is added, what is the pH then?

This one is easier. Once you add 0.0 mL of a strong base, pH doesn't change. But I suppose that's just a typo :smil:
 
  • #3
Problem description is incomplete. Are you trying to solve a general problem?
 

1. What is the purpose of a buffer solution?

A buffer solution is used to maintain a stable pH level in a system. It is composed of a weak acid and its conjugate base, or a weak base and its conjugate acid, which can neutralize any added acid or base and prevent drastic changes in pH.

2. How do you calculate the pH of a buffer solution?

The Henderson-Hasselbalch equation is used to calculate the pH of a buffer solution. It is pH = pKa + log([A-]/[HA]), where pKa is the negative logarithm of the acid dissociation constant, [A-] is the concentration of the conjugate base, and [HA] is the concentration of the weak acid.

3. What is the pKa value of a buffer solution?

The pKa value of a buffer solution is a measure of the strength of the weak acid or base in the solution. It is the pH at which the weak acid or base is 50% dissociated.

4. How do you prepare a buffer solution with a specific pH?

To prepare a buffer solution with a specific pH, you need to choose a weak acid and its conjugate base, or a weak base and its conjugate acid, with a pKa value closest to the desired pH. You then mix the two components in the correct ratio to achieve the desired pH.

5. How do you adjust the pH of a buffer solution?

The pH of a buffer solution can be adjusted by adding small amounts of a strong acid or base. This will shift the equilibrium between the weak acid and its conjugate base, resulting in a change in pH. It is important to add the acid or base slowly and monitor the pH to prevent drastic changes.

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