1. In order to make the Happily Ever After potion that Shrek needs, Donkey needs a buffer solution. Which of the following combinations make a buffer solution that will help Shrek have a happy ending?

   		a. HCN and KCN
   		b. HF and NaF
   		c. NH3 and (NH4)2SO4
   		d. HNO2 and NaNO2

2. For phosphoric acid, K_a1 = 7.3 10³, K_a2 = 6.2 10⁸, and K_a3 = 4.8 10¹³.

   Which of the following represents the conjugate acid-base pair pertaining to K_a2 ?

   		a. H2PO3 (aq) / HPO3(aq)
   		b. H2PO4 / HPO42
   		c. HPO42 / PO43
   		d. H3PO4 /H2PO4

3. You are in potions class at Hogwarts and Snape asks you to titrate a weak acid, H2SO3, with a strong base, RbOH. What type of salt would this produce, and sketch a titration curve for this reaction. Ps: Its the anniversary of Lilys death so Snape is extra picky; be sure to label your axes.