Help with this question please! Watch

EricRivers
Badges: 0
Rep:
?
#1
Report Thread starter 5 years ago
#1
Acetic Acid (CH3COOH) is a weak acid. Ka= 1.8x 10-5

1. Write a chemical equation for the dissociation of acetic acid?

CH3COOH ---> CH3COO- + H+

2. Write the equilibrium (Ka) expression for the reaction?
Ka= [H+] [CH3COO-]
[CH3COOH]

3. Vinegar is a solution of 1.5 M acetic acid. What is the pH of vinegar at this concentration?
I'm not sure, any suggestions?

These are my answers, are they correct? I really appreciate the help, I'm having a tough time with this problem
0
reply
charco
  • Study Forum Helper
Badges: 17
Rep:
?
#2
Report 5 years ago
#2
(Original post by EricRivers)
Acetic Acid (CH3COOH) is a weak acid. Ka= 1.8x 10-5

1. Write a chemical equation for the dissociation of acetic acid?

CH3COOH ---> CH3COO- + H+

2. Write the equilibrium (Ka) expression for the reaction?
Ka= [H+] [CH3COO-]
[CH3COOH]

3. Vinegar is a solution of 1.5 M acetic acid. What is the pH of vinegar at this concentration?
I'm not sure, any suggestions?

These are my answers, are they correct? I really appreciate the help, I'm having a tough time with this problem

check out this interactive on weak acids
0
reply
EricRivers
Badges: 0
Rep:
?
#3
Report Thread starter 5 years ago
#3
(Original post by charco)
check out this interactive on weak acids
wow that was very helpful, so would that make the pH for question 3 equal to a pH of 1.5? since it's a weak acid
0
reply
charco
  • Study Forum Helper
Badges: 17
Rep:
?
#4
Report 5 years ago
#4
(Original post by EricRivers)
wow that was very helpful, so would that make the pH for question 3 equal to a pH of 1.5? since it's a weak acid
ka = [H+][A-]/[HA]

1.8 x 10-5 = [H+]2/1.5

[H+] = root(1.5 x 1.8 x 10-5)

[H+] = root(2.7 x 10-5)

[H+] = 0.0052

pH = 2.28
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • Brunel University London
    Postgraduate Open Evening Postgraduate
    Wed, 22 May '19
  • University of Roehampton
    Postgraduate Open Evening Postgraduate
    Wed, 22 May '19
  • Sheffield Hallam University
    Postgraduate Open Day Postgraduate
    Wed, 22 May '19

How did your Edexcel GCSE Maths Paper 1 go?

Loved the paper - feeling positive (29)
23.77%
The paper was reasonable (49)
40.16%
Not feeling great about that exam (24)
19.67%
It was TERRIBLE (20)
16.39%

Watched Threads

View All