Journal Entry:

Caffeine (C₈H₁₀N₄O₂) is a weak base (K_B=4 X 10^-4). The pH of a 0.1 M solution of caffeine is approximately?
(A) 8
(B)10
(C)11
(D)12

Learning Intentions

• We will learn how to use your equation sheet to help you solve FRQ problems about equilibrium  

• We will learn what a buffer is and what kind of solutions make a good buffer.

• We will learn how a buffer works at the particle level while observing a real life buffer solution in action. 

Closing Task:

You can use buffer knowledge to solve acid-base equilibrium FRQs.

Content Standards being covered:

Chemical equilibrium reasoning can be used to describe the proton-transfer reactions of acid base chemistry. (E.K.6.C.1)

The pH is an important characteristic of aqueous solutions that can be controlled with buffers. Comparing pH to pKa allows one to determine the protonation state of a molecular with a labile proton. (E.K. 6.C.2)