Question

Which of the following solution can act as buffer :
(1) 0.2 M NaOH + 0.1 M HCl
(2) 0.1 M NH4OH + 0.1 M HCl
(3) 0.2 M AgOH + 0.1 M HNO3
(4) 0.1 M NH4OH + 0.2 M HCl

here, why is the answer 3 and not 2?

Answer 1

because a buffer solutions is formed by an light base and a strong acid..... or a light acid and a strong base

Answer 2

IN BUFFER SOLUTION THERE ARE WEAK ACID OR BASE WITH ITS SALT

Answer 3

NH4OH is a weak base and HCl is a strong acid.then y not that option?

Answer 4

@aqzbala for a buffer to happen, there has to be a weak acid and a weak base involved, from our options, you should know that HCl is a strong acid, so from what I just said, can HCl be involved in a buffer?

Answer 5

its actually a weak acid with its salt with a strong base or weak base with its salt with a strong acid no?

Answer 6

All you have to remember that strong bases, or strong acids can not be in a buffer, that's how I remember it. As long as you remember your strong acids's and base's you should know. @aqzbala

Answer 7

imeant CH3COOH and CH3COONa do they form an acid buffer?

Answer 8

What do you mean acid buffer?

Answer 9

there are acid buffers and basic buffers no?
omg..i got totally confused now....is there another group of simple buffers with weak acid and weak base?
where has my concept gone wrong? pls do clarify!

Answer 10

weak acid-base conjugate pair that keeps the pH from changing

That's all you have to remember. If you have a strong Acid and a weak base, this is not a buffer, if you have a strong base and a weak acid, this is not a buffer.

If you have a weak acid, and a weak base, this is a buffer.

Answer 11

Strong Acids.
HI H+(aq) + I-(aq)
HBr H+(aq) + Br-(aq)
HClO4 H+(aq) + ClO4-(aq)
HCl H+(aq) + Cl-(aq)
HClO3 H+(aq) + ClO3-(aq)
H2SO4 H+(aq) + HSO4-(aq) (HSO4- is a weak acid that
contributes additional protons)
HNO3 H+(aq) + NO3-(aq)

Strrong bases:
NaOH Na+(aq) + OH-(aq)
KOH K+(aq) + OH-(aq)
LiOH Li+(aq) + OH-(aq)
RbOH Rb+(aq) + OH-(aq)
CsOH Cs+(aq) + OH-(aq)
Ca(OH)2 Ca2+(aq) + 2OH-(aq) (but not very soluble)
Ba(OH)2 Ba2+(aq) + 2OH-(aq) (but not very soluble)
Sr(OH)2 Sr2+(aq) + 2OH-(aq) (but not very soluble)

Most of the time if you see any of these, buffers can not be produced.

Answer 12

that means how a buffer is formed?
mixing weak base and acid or simply aqueous solution of a weak acid or base? is it so?

Answer 13

Yes. And because HCl is a strong acid, there is no way that anything mixed with a strong acid like that can be a buffer.

Answer 14

okies... :)
thanks alot!

Answer 15

HOWEVER there are some exceptions, but that's for like wayy higher up education level, so for now you are good.

Answer 16

can u answer one another doubt?

Answer 17

do 2nd period elements show excitation of electrons?