Which will act as a buffer solution

Which of the following mixtures will act as a buffer solution when dissolved in 50 mL of water ?

Count the number of pairs which may act as a buffer solution when present in a given solution (a) CH_(3)COOH +NaOH (b) (c) NH_(4)CI + HNO_(3) (d) HCIO_(4) +KCIO_(4) (e) H_(3)PO_(4)+NaOH (f) H_(3)PO_(3) +NaOH (g) NaHCO_(3) + Na_(2)CO_(3) (h) H_(2)SO_(4) + Na_(2)SO_(4) (i) CH_(3) COONa + HCI (j)

Which is a buffer solution?

which can act as buffer ?

which can act as buffer ?

Which can act as buffer?