Which of the following aqueous solutions are good buffer systems?
0.23 M nitric acid + 0.18 M sodium nitrate
0.13 M calcium hydroxide + 0.24 M calcium chloride
0.19 M hydrofluoric acid + 0.11 M sodium fluoride
0.35 M hypochlorous acid + 0.28 M potassium hypochlorite
0.34 M ammonium nitrate + 0.36 M ammonia
Correct choices are 3), 4) and 5)
Reason:
Buffers are formed by weak acid and its salt, weak base and its salt or salt or weak acid and weak base.
Strong acid/strong bases and their salts cannot form buffer solutions. [So, 1) and 2) do not form buffers]
3) and 4) are mixtures of weak acids and their salts with strong bases.
5) is a mixture of weak base and its salt with strong acid.