Question

A buffer is prepared by mixing 25.0 ml of 1.00 NaC2H3O2 with 25.0 ml of 0.900...

A buffer is prepared by mixing 25.0 ml of 1.00 NaC2H3O2 with 25.0 ml of 0.900 M HC2H3O. If 20 ml of 0.50 M HCl is added to the initial buffer solution, what is the pH?

Science   Chemistry   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

by adding HCl to the buffer following reaction takes place

C2H3O2- + H+   ---------------------> HC2H3O2

millimoles of NaC2H3O2 = 25 x 1.0 = 25

millimoles of HC2H3O2 = 25 x 0.9 = 22.5

millimoles of HCl added = 20 x 0.5 = 10

after HCl added

millimoles of NaC2H3O2 = 25 - 10 = 15

millimoles of C2H3O2 = 22.5 + 10 = 32.5

total volume = 25 + 25 + 20 = 70

[NaC2H3O2] = 15 / 70 = 0.214 M

[HC2H3O2] = 32.5 / 70 = 0.464 M

pKa of HC2H3O2 = 4.75 standard value

pH = pKa + log [NaC2H3O2] / [HC2H3O2]

pH = 4.75 + log [0.214] / [0.464]

pH = 4.75 - 0.336

pH = 4.414

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Calculate the pH of a buffer solution prepared by mixing 50.0 mL of 1.00 M lactic...
Calculate the pH of a buffer solution prepared by mixing 50.0 mL of 1.00 M lactic acid and 25.0 mL of 0.75 M sodium lactate.
A buffer is prepared by mixing 50.0 mL of 0.050 M acetic acid and 20.0 mL...
A buffer is prepared by mixing 50.0 mL of 0.050 M acetic acid and 20.0 mL of 0.10 M sodium hydroxide. a) What is the pH? b) How many grams of HCl must be added to 25.0 mL of the buffer to change the pH by 0.07 units?
A buffer solution is prepared by mixing 50.0 mL of 0.300 M NH3(aq) with 50.0 mL...
A buffer solution is prepared by mixing 50.0 mL of 0.300 M NH3(aq) with 50.0 mL of 0.300 M NH4Cl(aq). The pKb of NH3  is 4.74. 7.50 mL of 0.125 M NaOH is added to the 100.0 mL of the original buffer solution prepared in Question 1 (no HCl added). Calculate the new NH3 concentration for the buffer solution. Calculate the new NH4Cl concentration for the buffer solution. Calculate the new pH of the solution.
a buffer is prepared by mixing 500 ml of 0.2 M Na2HPO4 with 500 ml of...
a buffer is prepared by mixing 500 ml of 0.2 M Na2HPO4 with 500 ml of 0.4 M NaH2PO4. a) what is the pH of this buffer B) if 10ml of 1 M HCL was added to this buffer what change in pH would be observed (ignore any change in volume) c) what would the final pH be if you added the same quantity of acid to 1 l of H2O (pH 7) please show all steps
a buffer solution is prepared by mixing 45.0 mL of 0.100M NH3 are mixed with 25.0...
a buffer solution is prepared by mixing 45.0 mL of 0.100M NH3 are mixed with 25.0 mL of 0.200M NH4Cl. calculate the pH of the solution and, with the help of appropriate chemical equations, describe how this buffer works. Include some comments about its capacity for absorbtion of strong acid and strong base.
What is the pH of a solution that is prepared by mixing 25.0 mL of 0.33...
What is the pH of a solution that is prepared by mixing 25.0 mL of 0.33 M hydrochloric acid and 25.0 mL of 0.58 M ammonia? Question 9 options: 4.62 8.99 9.37 3.87 9.13
What is the pH of a buffer prepared by mixing 20.0 mL of a 0.277 M...
What is the pH of a buffer prepared by mixing 20.0 mL of a 0.277 M HNO2 solution with 30.0 mL of a 0.170 M NaNO2 solution?
10 mL of 0.0100 M HCl are added to 25.0 mL of a buffer solution that...
10 mL of 0.0100 M HCl are added to 25.0 mL of a buffer solution that is 0.010 M HC2H3O2 and 0.1 M C2H3O2-. What is the pH of the resulting solution?
QUESTION 1: A buffer is prepared by mixing 192 mL of 0.452 M HCl and 0.485...
QUESTION 1: A buffer is prepared by mixing 192 mL of 0.452 M HCl and 0.485 L of 0.400 M sodium acetate. (See this table.) pH is 4.83. How many grams of KOH must be added to 0.500 L of the buffer to change the pH by 0.18 units? QUESTION 2: 60.0 mL of a 0.350 M solution of a weak acid are titrated with 0.250 M NaOH. What is the pH when 57% of the acid has been titrated?...
A pH 9.56 buffer was prepared by mixing 2.00 moles of ammonia (Kb for ammonia is...
A pH 9.56 buffer was prepared by mixing 2.00 moles of ammonia (Kb for ammonia is 1.8 × 10-5) and 1.00 mol of ammonium chloride in water to form a solution with a volume of 1.00 L. To a 200.0 mL aliquot of this solution was added 10.0 mL of 10.0 M sodium hydroxide. What was the resulting pH? Please show full work with explanation. Thank you.
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT