Preparing Buffer Solutions: Calculating the Number of Grams of Conjugate Base Needed Use the table of K...

80.2K

Verified Solution

Question

Chemistry

Preparing Buffer Solutions: Calculating the Number of Grams ofConjugate Base Needed

Use the table of K values given with this problem to choose thebest weak acid to start from for making a buffer that holds the pHof the solution at 3.20. Make your selection so that you maximizethe capacity of the buffer.
You select a 200.0 ml volumetric flask to which you add 54.00 mL ofa 2.90 M solution of the weak acid you just selected. To finishpreparing your buffer you must now add the sodium salt of theconjugate base. How many grams of the sodium salt of your conjugatebase must you add so that when you finally fill the flask to themark with deionized water the buffer will have a pH of 3.20.
Weak Acid K_a
CH₃COOH (Acetic Acid) 1.8 X 10^-5
C₆H₅COOH (Benzoic Acid) 6.5 X 10^-5
CH₃CH₂CH₂COOH (ButanoicAcid) 1.5 X 10^-5
HCOOH (Formic Acid) 1.8 X 10^-4
HBrO (Hypobromous Acid) 2.8 X 10^-9
HNO₂ (Nitrous Acid) 4.6 X 10^-4
HClO (Hypochlorous Acid) 2.9 X 10^-8
CH₃CH₂COOH (Propanoic Acid) 1.3 X 10^-5
HCN (Hydrocyanic Acid) 4.9 X 10^-10
I posted this question before and they got the answer of 8.00gwhich is NOT CORRECT, so I was looking someone else to help me withthis.

Answer & Explanation Solved by verified expert

4.1 Ratings (449 Votes)

sodium salt of conjugate base 788 g Explanation Given pH of buffer 320 pKa of the acid should be closest to pH of buffer for an effective buffer acid See Answer

Get Answers to Unlimited Questions

Join us to gain access to millions of questions and expert answers. Enjoy exclusive benefits tailored just for you!

Membership Benefits:

Unlimited Question Access with detailed Answers
Zin AI - 3 Million Words
10 Dall-E 3 Images
20 Plot Generations
Conversation with Dialogue Memory
No Ads, Ever!
Access to Our Best AI Platform: Flex AI - Your personal assistant for all your inquiries!

Become a Member

Weak Acid	K_a
CH₃COOH (Acetic Acid)	1.8 X 10^-5
C₆H₅COOH (Benzoic Acid)	6.5 X 10^-5
CH₃CH₂CH₂COOH (ButanoicAcid)	1.5 X 10^-5
HCOOH (Formic Acid)	1.8 X 10^-4
HBrO (Hypobromous Acid)	2.8 X 10^-9
HNO₂ (Nitrous Acid)	4.6 X 10^-4
HClO (Hypochlorous Acid)	2.9 X 10^-8
CH₃CH₂COOH (Propanoic Acid)	1.3 X 10^-5
HCN (Hydrocyanic Acid)	4.9 X 10^-10