May 08, 2021, 06:44:44 PM
Forum Rules: Read This Before Posting


Topic: Conjugate acids and bases  (Read 8022 times)

0 Members and 1 Guest are viewing this topic.

Offline huskywolf

  • Full Member
  • ****
  • Posts: 126
  • Mole Snacks: +1/-8
  • Gender: Male
Conjugate acids and bases
« on: December 09, 2009, 02:26:37 PM »
Question 1.
What are the following conjugate bases?

a.         H2O
b.           CH3COOH
c.            HS-
d.              NH4+
I THINK ONLY c. IS THIS CORRECT?

what are the following conjugate acids?
e.NH3
f.S2-
g.CO32-
h.NH2-
I DONT SEE ANY?

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3541
  • Mole Snacks: +218/-42
  • Gender: Male
Re: Conjugate acids and bases
« Reply #1 on: December 09, 2009, 03:04:48 PM »
What definition of acid and base are you using?

Offline savy2020

  • Full Member
  • ****
  • Posts: 150
  • Mole Snacks: +7/-9
  • Gender: Male
Re: Conjugate acids and bases
« Reply #2 on: December 09, 2009, 03:09:34 PM »
Just a clarification- you mean What are... OR Which of these are... ?

I'm assuming the meaning of questions as -- Which of the below chemicals can be conjugate _______ of some others.

Quote
Question 1.
What are the following conjugate bases?

a.         H2O
b.           CH3COOH
c.            HS-
d.              NH4+
I think A,B and C can be conjugate bases of some other chemicals but not NH4+

Quote
what are the following conjugate acids?
e.NH3
f.S2-
g.CO32-
h.NH2-
All the four are correct

{OR is it that For which of these chemicals conjugate _______ exist}

Surely one has to use BRONSTED theory in order to talk of Conjugate Acids/Bases
:-) SKS

Offline huskywolf

  • Full Member
  • ****
  • Posts: 126
  • Mole Snacks: +1/-8
  • Gender: Male
Re: Conjugate acids and bases
« Reply #3 on: December 09, 2009, 03:47:18 PM »
Hello,Thanks for the reply
The question on the paper does not say 'which'
It says
What are the conjugate bases of each of the following?

Offline savy2020

  • Full Member
  • ****
  • Posts: 150
  • Mole Snacks: +7/-9
  • Gender: Male
Re: Conjugate acids and bases
« Reply #4 on: December 09, 2009, 03:49:40 PM »
Remove H+ from each you'll get Conjugate base
and add H+ to each in next Q you'll have Conjugate acid
What's problem with that.. I can't understand
 :D
:-) SKS

Offline huskywolf

  • Full Member
  • ****
  • Posts: 126
  • Mole Snacks: +1/-8
  • Gender: Male
Re: Conjugate acids and bases
« Reply #5 on: December 09, 2009, 04:08:26 PM »
It makes sense now thanks
I thought it meant pick out the conjugate acids or bases as they are just by looking at the question
not actually + or - H

Offline huskywolf

  • Full Member
  • ****
  • Posts: 126
  • Mole Snacks: +1/-8
  • Gender: Male
Re: Conjugate acids and bases
« Reply #6 on: December 09, 2009, 04:10:22 PM »
one more question
should I include the little delta beside the + or - when indicating for conjugate acids or bases

Offline savy2020

  • Full Member
  • ****
  • Posts: 150
  • Mole Snacks: +7/-9
  • Gender: Male
Re: Conjugate acids and bases
« Reply #7 on: December 09, 2009, 04:20:11 PM »
No delta means a partial charge
But + without delta means charge on electron
H+ is formed from H by losing one electron
:-) SKS

Offline huskywolf

  • Full Member
  • ****
  • Posts: 126
  • Mole Snacks: +1/-8
  • Gender: Male
Re: Conjugate acids and bases
« Reply #8 on: December 09, 2009, 04:23:19 PM »
Ok thanks

Offline huskywolf

  • Full Member
  • ****
  • Posts: 126
  • Mole Snacks: +1/-8
  • Gender: Male
Re: Conjugate acids and bases
« Reply #9 on: December 12, 2009, 06:17:18 AM »
My exam is next week and I want to be certain I understand these correctly please tell me if these are the correct answers
Question 1.
What are the following conjugate bases of each of these?

a.         H2O=HO-
b.           CH3COOH=CH3OO-
c.            HS-=S-2
d.              NH4+=NH3-
 IS THIS CORRECT?

what are the following conjugate acids?
e.NH3=NH4+
f.S2-=HS2+
g.CO32-=HCO3+  or no H?
h.NH2-=NH3+

Please answer soon  ;)

Offline savy2020

  • Full Member
  • ****
  • Posts: 150
  • Mole Snacks: +7/-9
  • Gender: Male
Re: Conjugate acids and bases
« Reply #10 on: December 12, 2009, 06:37:32 AM »
d.              NH4+=NH3-
f.S2-=HS2+
g.CO32-=HCO3+
h.NH2-=NH3+
You went wrong with the charge in the above answers. No probs try again
Pls again read this
Remove H+ from each you'll get Conjugate base
and add H+ to each in next Q you'll have Conjugate acid
 
Treat the atoms and charge seperately.
i.e, to get conjugate base remove a H and also a +ve charge.
Try the above again and post. We'll see :D

Also pls use subscripts and superscripts often lest you may confuse charge with atoms
:-) SKS

Offline huskywolf

  • Full Member
  • ****
  • Posts: 126
  • Mole Snacks: +1/-8
  • Gender: Male
Re: Conjugate acids and bases
« Reply #11 on: December 12, 2009, 08:50:18 AM »
Hello,

D= NH3
F=HS2
G=HCO3
H=NH3
??

Offline savy2020

  • Full Member
  • ****
  • Posts: 150
  • Mole Snacks: +7/-9
  • Gender: Male
Re: Conjugate acids and bases
« Reply #12 on: December 12, 2009, 10:50:33 AM »
F=HS2
G=HCO3

You seem to have difficulties with charge. Do the following it may clear the concepts a bit.

OK what is the equation of addition of H+ toS2-?
S2- + H+  :rarrow: HS?? -
Fill in the charge so that net charge on LHS is equal to that on the RHS

Similarly for the other one..
CO32- + H+  :rarrow: HCO3??

Please write such equations for all others which you've got correct so that you may not confuse on some other question :)
And all the best for your exam. Prepare well ;D
:-) SKS

Offline huskywolf

  • Full Member
  • ****
  • Posts: 126
  • Mole Snacks: +1/-8
  • Gender: Male
Re: Conjugate acids and bases
« Reply #13 on: December 12, 2009, 01:13:30 PM »
I'm not sure  ???
F=HS-
G=HCO3-

but these would not be acids then?

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3541
  • Mole Snacks: +218/-42
  • Gender: Male
Re: Conjugate acids and bases
« Reply #14 on: December 12, 2009, 01:48:53 PM »
I'm not sure  ???
F=HS-
G=HCO3-

but these would not be acids then?

Why do you feel they are not now acids?

Sponsored Links