# chem

posted by .

I got part 1:

What is the pH of the solution created by combining 1.10 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)? with 8.00 mL of the 0.10 M HC2H3O2(aq)?

pH w/HCl =1.12 w/HC2H3O2(aq)= 3.94

But how do you do part two?

What are the pH values if you take into account that the 8.00 mL of 0.10 M Acid was first diluted with 100 mL of water (like it will be in the experiment you perform in lab)?

thanks

• chem -

How did you do part 1. You had moles NaOH and moles HCl (HCl in excess), yo subtracted moles HCl-moles NaOH to arrive at moles HCl in excess. I think that is 0.69 millimoles and that divided by the volume (8 mL + 1.1 mL = 9.1 mL) = 0.0758 M and pH = 1.12. So for part 2, you have the same of everything except the 0.69 millimoles is now in 100 + 1.1 = 101.1 mL. Convert that to pH.

The 3.94 you obtained for the initial part was obtained by using the Henderson-Hasselbalch equation. That is
pH = pKa + log (base)/(acid)
Notice, however, in this one that the pH is determined by a ratio (not like HCl/NaOH). When you dilute the base by what ever factor (8 mL up to 100) that it dilutes BOTH the base AND the acid the same amount and since mole/L is concn, the volume cancels and its just moles/moles and the volume doesn't matter. The end result is that dilution has no effect on the buffer solution.

## Similar Questions

1. ### chemistry

What is the pH of the solution created by combining 2.80 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
2. ### chem urgent!!

What is the pH of the solution created by combining 12.00 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
3. ### Chemistry

What is the pH of the solution created by combining 11.40 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
4. ### Chemistry

What is the pH of the solution created by combining 12.20 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
5. ### CHEMISTRY (WEBWORK)

What is the pH of the solution created by combining 1.20 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
6. ### Chem Webwork UCI

Complete the table below: What is the pH of the solution created by combining 0.70 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
7. ### chem

What is the pH of the solution created by combining 2.40 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
8. ### Chemistry

1. A good indicator will have a(n)____ close to this volume and pH. I think it's endpoint but it's wrong. 2. (part a) What is the pH of the solution created by combining 1.70 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
9. ### Chemistry

What is the pH of the solution created by combining 12.30 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?
10. ### Chemistry

What is the pH of the solution created by combining 12.30 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)?

More Similar Questions