# Biochemistry

posted by Shalette

Calculate the pH of a mixture of one mole of benzoic acid and two mole of sodium benzoate dissolved in 1 L of solution. The pKa of benzoic acid is 4.2. What is the final molar concentration of the buffer?

1. DrBob222

pH = pKa + log (base)/(acid)
(acid) = mols benzoic acid/1 L = ?
(base) = mols sodium benzoate/1 L = ?
Substitute and solve for pH.

Final concentration of buffer = total mols/total L = mols acid + mols base/total mols = 3 mol/L = ?

## Similar Questions

1. ### Chem

I am having the following problem: I need to calculate 2 Keq values based on the experiment that I conducted. I reacted 0.082 moles of benzoic acid with 0.618 moles of methanol and obtained 0.055 moles of methyl benzoate. When I calculate …
2. ### Chemistry

Calculate the pH of a buffer solution that contains 0.23 M benzoic acid (C6H5CO2H) and 0.28 M sodium benzoate (C6H5COONa). [Ka = 6.5 × 10-5 for benzoic acid] Please help?
3. ### Chemistry

Given that the Ka of benzoic acid is 6.50 x 10-5, how would one prepare 0.500 L of a benzoic acid/sodium benzoate buffer of a desired pH of 4.00?
4. ### Chemistry

Given that the Ka of benzoic acid is 6.50 x 10-5, how would one prepare 0.500 L of a benzoic acid/sodium benzoate buffer of a desired pH of 4.00?
5. ### chemistry

How do I do a question like this please help and explain it!! Calculate the pH of a buffer solution that contains 0.22 M benzoic acid (C6H5CO2H) and 0.24 M sodium benzoate (C6H5COONa). [Ka = 6.5 × 10-5 for benzoic acid] Round your …
6. ### Chemistry

1. Calculate the pH of a buffer solution that contains 0.32 M benzoic acid (C6H5CO2H) and 0.17 M sodium benzoate (C6H5COONa). [Ka = 6.5 × 10-5 for benzoic acid] Round your answer to two places past the decimal. 2. A solution is prepared …
7. ### Chemistry

1. Calculate the pH of a buffer solution that contains 0.32 M benzoic acid (C6H5CO2H) and 0.17 M sodium benzoate (C6H5COONa). [Ka = 6.5 × 10-5 for benzoic acid] Round your answer to two places past the decimal. 2. A solution is prepared …
8. ### ap chemistry

What is the concentration of H+ ions in a buffer solution containing 0.305 M benzoic acid (with ionization constant 6.5 × 10−5)and 0.834 M sodium benzoate (a salt of benzoic acid)?
9. ### Chemistry

Determine the pH of the following solutions: a) A 250.0 mL solution that contains 0.125 M benzoic acid and 0.147 M sodium benzoate. b) The solution in part (a) after 30.0 mL of 0.510 M hydrochloric acid has been added. a. Ka = 6.3 …
10. ### Chemistry

You need to prepare 100.0 mL of a pH=4.00 buffer solution using 0.100 M benzoic acid (pKa = 4.20) and 0.220 M sodium benzoate. How much of each solution should be mixed to prepare this buffer?

More Similar Questions