How to determine if the mixing of two solution would result in buffer solution?

ada15

1. The problem statement, all variables and given/known data
Which of the following mixtures would result in buffered solutions whn 1.0 L of each of the two solutions are mixed?

(i) 0.10 M sodium chloride and 0.10 M sodium nitrite
(ii) 0.10 M sodium chloride and 0.10 M ammonium chloride
(iii) 0.10 M hydrochloric acid and 0.10 M ammonia
(iv) 0.20 M hydrochoric acid and 0.10 M ammonia
(v) 0.10 M hydrochloric acid and 0.20 M ammonia


2. Relevant equations

All I know is that there are 6 methods by which we can buffer solutions:
(i) weak acid and strong base
(ii) weak base ans strong acid
(iii) weak and its salt
(iv) weak base and its salt
(v) salt of weak acid and strong acid
(vi) salt of weak base and strong base


3. The attempt at a solution

but when I use the above knowledge, the answer are coming different ... the thing I'm not getting is how the molarity of each of the solutions would have an effect.

I have the answers for the above parts but I don't know the reasoning .....

(i) No
(ii) No
(iii) No
(iv) No
(v) Yes


Can anyone please please immediately and somehow explain me the reasoning ...... I'll be really thankful ....

Borek

Buffer must contain conjugated pair of acid/base. Preparation methods are a consequence of this.

Borek
--
Chemical calculators at www.chembuddy.com
equation balancer and stoichiometry calculator
pH calculator
concentration conversion

ada15

Hey there, thankyou for the links , but do you know how to find the answers without using chemical calculator ... I've an exam tomorrow.

Borek

Too late I presume... But to find the answers to your questions you should follow not my links, but information about what the buffer is. Take a look at all solutions defined - IF they contain both acid and conjugated base (especially in comparable quantities) you have a buffer solution.

Borek
--
General Chemistry Software
www.pH-meter.info/pH-electrode