What mass of NaC₂H₃O₂ (molar mass = 82.03 g/mol) would need to be added to 0.450 moles of HC₂H₃O₂ to prepare a 1.0 L buffer with a pH = 4.95. K_a for HC₂H₃O₂ = 1.8 × 10⁻⁵.

Which pairs of compounds are capable of making a buffer? Select all that apply.

a) 1.3 M LiOH and 1.7 M HCOOH                        c) 0.35 M CH₃CO₂H and 0.35 M NaOH

b) 0.784 M NH₄⁺ and 0.800 M HClO₄                  d) 0.80 HNO₃ and 0.15 MgO

Determine which of the following actions will destroy a buffer composed of 0.50 L of 1.44 M H₃PO₄ and 0.60 L of 1.25 M NaH₂PO₄⁻.

a) Addition of 1.45 moles of KH₂PO₄

b) Addition of 0.85 moles of HCl

c) Addition of water

d) Addition of 0.30 moles of Ca(OH)₂

e) Addition of 0.70 moles of HIO₄

A buffer resists change in ph when ___________ amount of acid or base is added to it.