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TeenieBopper
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I have two questions about pH of buffers. It's a general chemistry class, but the questions aren't similar to anything we've had yet.
A buffer is prepared by adding 0.96 L of 0.96 M HCl to 762 mL of 1.4 M NaHCOO. What is the pH of this buffer? [Ka(HCOOH) = 1.7 × 10-4]
pH=pKa+log([A-]/[HA]
It's the fact that it's HCl that's really throwing me off. I thought a buffer could only be made with a weak acid and it's conjugate base (and vice versa). I can figure out the pH of the HCl and the NaHCOO solutions without a problem, but it's the combining that's throwing me.
A certain monoprotic weak acid with Ka = 0.37 can be used in various industrial processes. (a) What is the [H+] for a 0.234 M aqueous solution of this acid and (b) what is its pH?
Ka=[H+][A-]/[HA]
pH=-log[H+]
I did an ICE table and set up the equation .37=x^2/(.234-x) to get [H+]. Once I had that, -log[H+] gave me the pH. I got [H+]=.1625 and pH=.79, which doesn't make sense at all considering it's supposed to be a weak acid, but I'm not sure what I'm doing wrong.
Homework Statement
A buffer is prepared by adding 0.96 L of 0.96 M HCl to 762 mL of 1.4 M NaHCOO. What is the pH of this buffer? [Ka(HCOOH) = 1.7 × 10-4]
Homework Equations
pH=pKa+log([A-]/[HA]
The Attempt at a Solution
It's the fact that it's HCl that's really throwing me off. I thought a buffer could only be made with a weak acid and it's conjugate base (and vice versa). I can figure out the pH of the HCl and the NaHCOO solutions without a problem, but it's the combining that's throwing me.
Homework Statement
A certain monoprotic weak acid with Ka = 0.37 can be used in various industrial processes. (a) What is the [H+] for a 0.234 M aqueous solution of this acid and (b) what is its pH?
Homework Equations
Ka=[H+][A-]/[HA]
pH=-log[H+]
The Attempt at a Solution
I did an ICE table and set up the equation .37=x^2/(.234-x) to get [H+]. Once I had that, -log[H+] gave me the pH. I got [H+]=.1625 and pH=.79, which doesn't make sense at all considering it's supposed to be a weak acid, but I'm not sure what I'm doing wrong.