# chemistry

•Which of the following solutions will be the best buffer at a pH of 9.26? (Ka for HC2H3O2 is 1.8 x 10–5; Kb for NH3 is 1.8 x 10–5.)
a)0.20 M HC2H3O2 and 0.20 M NaC2H3O2
b)3.0 M HC2H3O2 and 3.0 M NH4Cl
c)0.20 M NH3 and 0.20 M NH4Cl
d)3.0 M NH3 and 3.0 M NH4Cl
e)3.0 M HC2H3O2 and 3.0 M NH3

actually, i used pH= pKa+ log(base/acid)
9.26=9.26+ log base/acid
I know [base]=[acid]
but how i can choose between 3.0M or 0.20M of NH3 ? (why answer is d not c?)

1. 👍
2. 👎
3. 👁
1. Both c and d give you pH 9.26 since base/acid = 1 and log 1 = 0. But d is the better answer because the more concentrated solutions make the buffer capacity larger; i.e., the more concentrated solutions can handle MORE of an added base and/or acid before changing more than +/- 1 pH.

1. 👍
2. 👎

## Similar Questions

1. ### Math

How many real number solutions does the equation have? y=3x^2-5x-5 A)one solution B)two solutions C)no solutions D)infinitely many solutions I can't figure this question out. Any help would be amazing.

2. ### Chemistry

Select the statements that correctly describe buffers.? 1) The pH of a buffer solution does not change significantly when any amount of a strong acid is added. 2) The Ka of a buffer does not change when any amount of an acid is

3. ### algebra

how many real number solutions does the equation have? 0=2x^2-20x+50 A. 1 solution B. 2 solutions C. no solutions** D. infinite solutions

4. ### chemistry

If you add 5.0 mL of 0.50 M NaOH solution to 20.0 mL to Buffer C, what is the change in pH of the buffer? (where buffer C is 8.203 g sodium acetate with 100.0 mL of 1.0 M acetic acid) I have calculated the pH of buffer C to be

1. ### Math

1)How many real number solutions does the equation have? -8x^2-8x-2=0 A) One Solution B) Two Solutions C) No solutions D) Infinitely many solutions If someone could help me with this that would be great since I am confused. Thank

2. ### chemistry

I have many questions. I have a test tuesday and need to get these problems done and understand them today because i am currently studying. I am in college and my professor has not emailed me back regarding solutions for the

3. ### chemistry

A buffer is made by dissolving H3PO4 and NaH2PO4 in water. a. write an equation that shows how this buffer neutralizes a small amount of acids. b. write an equation that shows how this buffer neutr?

4. ### chemistry

Of the following solutions, which has the greatest buffering capacity? A) 0.821 M HF and 0.909 M NaF B) They are all buffer solutions and would all have the same capacity. C) 0.100 M HF and 0.217 M NaF D) 0.121 M HF and 0.667 M

1. ### Chemistry

A buffer consisting of H2PO4- and HPO42-, helps control the pH of physiological fluids. Many carbonated soft drinks also use this buffer system. You were asked to prepare this buffer from K2HPO4 and KH2PO4. Identify the week acid

2. ### Chem--buffers

Explain why a mixture formed by mixing 100 mL of 0.100M CH3COOH and 50 mL of 0.100M NaOH will act as a buffer? in adittion to this, how do you identify if a an aqueous solution is a buffer solution, such as a solution with an acid

3. ### Math

How many real-number solutions does the equation have? –7x2 + 6x + 3 = 0 one solution two solutions*********** no solutions infinitely many solutions

4. ### Chemistry

1.)An ammonia/ammonium buffer solution contains 0.35 M NH3 and 0.72 M NH4+. The Kb value of ammonia is 1.8×10−5. Calculate the pH of this buffer. 2.) Nitrous acid has a Ka of 4.5×10−4. What is the pH of a buffer solution