Question

Which of the following aqueous solutions are good buffer systems? and Why?
.

0.19 M potassium hydroxide + 0.27 M potassium bromide.

0.28 M hydroiodic acid + 0.18 M sodium iodide.

0.30 M ammonia + 0.37 M ammonium nitrate.

0.17 M hypochlorous acid + 0.12 M hydrobromic acid.

0.38 M calcium bromide + 0.30 M barium bromide.

Answer 1

answer :0.30 M ammonia + 0.37 M ammonium nitrate.it is good buffer

in order to get buffer solution we need to use

a) weak acid + its salt of stron base ---------------> ex: CH3COOH + CH3COONa

b) weak base + its salt of strong acid--------------> ex: NH4OH + NH4Cl

c ) weak acid + weak base compound--------------> ex : CH3COONH4

in the following question these are not buffers

1) 0.19 M potassium hydroxide + 0.27 M potassium bromide.

   it is strong base + strong salt mixture it cannot be act as a buffer

2) 0.28 M hydroiodic acid + 0.18 M sodium iodide.

    HIO4 + NaI it is also strong acid strong salt mixture

3) 0.17 M hypochlorous acid + 0.12 M hydrobromic acid.

      here these two are acids it cannot be buffer

4) 0.38 M calcium bromide + 0.30 M barium bromide.

    these two are salts of strong acid and strong base it cannot be buffer