Calculating pH of 0.001 M NaCl

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In summary, The pH of a 0.001 M NaCl solution will ideally be 7. Strong electrolytes, such as NaCl, will not affect the pH of the solution as their acids/bases are also strong electrolytes. While ionic strength is important in buffer preparation, it is not a significant factor in the pH of this solution. However, it is always important to consider the effect of neutral salts on pH in any solution containing ions.
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AdnamaLeigh
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How do you calculate the pH of 0.001 M NaCl? I was thinking of doing NaCl + H2O ---> HCl + NaOH but I don't know where to go from there if that's even the right step.
 
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Sodium Chloride is a strong electrolyte meaning it will disassociate completely in solution.
Strong electrolytes will not affect the pH of the solution as the acids / bases they form are also strong electrolytes.

A NaCl solution of any concentration should have (ideally) a pH of 7.


NaCl (aq) + H2O (l) ---> HCl (aq) + NaOH (aq)
HCl (aq) + NaOH (aq) --> NaCl (aq) + H2O (l)
 
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  • #4
The topic of ionic strength is practical with buffer preparation, however, I don't believe that it's an important factor with regard to the pH in this situation.
 
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GCT said:
The topic of ionic strength is practical with buffer preparation, however, I don't believe that it's an important factor with regard to the pH in this situation.

It is an important factor in every solution containing ions. Even if it doesn't change numerical value of pH in this case, you can't assume that addition of neutral salt never changes pH of the solution.
 

1. How do you calculate the pH of 0.001 M NaCl?

To calculate the pH of 0.001 M NaCl, you need to use the formula pH = -log[H+], where [H+] is the concentration of hydrogen ions in the solution. Since NaCl is a strong electrolyte, it dissociates completely into Na+ and Cl- ions. Therefore, the concentration of [H+] in the solution is equal to the concentration of [Cl-].

2. What is the concentration of [H+] in a 0.001 M NaCl solution?

The concentration of [H+] in a 0.001 M NaCl solution is also 0.001 M, as explained in the previous answer. This is because the concentration of [H+] is equal to the concentration of [Cl-] in a solution of a strong electrolyte like NaCl.

3. Why is the pH of a 0.001 M NaCl solution neutral?

The pH of a solution is determined by the concentration of hydrogen ions. In a 0.001 M NaCl solution, the concentration of [H+] is 0.001 M, which is considered a very low concentration. At this concentration, the solution is considered neutral, with a pH of 7 on the pH scale.

4. Can the pH of a 0.001 M NaCl solution change?

No, the pH of a 0.001 M NaCl solution cannot change. Since NaCl is a strong electrolyte, it completely dissociates into its ions and does not undergo any chemical reactions to produce or consume hydrogen ions. Therefore, the concentration of [H+] remains constant at 0.001 M, resulting in a constant pH of 7.

5. How does the concentration of NaCl affect the pH of a solution?

The concentration of NaCl does not directly affect the pH of a solution. However, it indirectly affects the pH by altering the concentration of [H+] through the process of dissociation. A higher concentration of NaCl will result in a higher concentration of [H+], leading to a lower pH, and vice versa.

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