Midterm #1 Review

Miscellaneous

100

What does a lower pKa value tell you about an acid's strength?

The acid is stronger

200

What is the Henderson-Hasselbach equation?

pH = pKa + log([A^-]/[HA])

pH = pKa + log(proton acceptor/proton donor)

300

Explain the trend in acid strength by row and by column.

Row: greater the EN, the stronger the acid

Column: the larger the atomic radius, the stronger the acid

Aqueous Solutions

100

What is the pH of a 0.040M solution of KOH?

12.6

200

Given a pH of 8.52, calculate the concentration of hydroxide ions.

3.31 x 10^-6

400

Find the pH of a solution made from 1.5g of NaOH dissolved in 1.00L of H₂O.

12.57

Salt Solutions

100

Will NaCl have a pH above, below, or equal to 7?

Equal to 7

200

What type of solution is formed from a strong base and weak acid.

Basic solution

Buffers

100

What are two components that are required to make a buffer?

Weak acid and its conjugate base

Weak base and its conjugate acid

200

If a strong base is added to a buffer with NaCH₃COO and CH₃COOH, what ion will it react with? And what will it form?

OH^- ions will react with the acetic acid (CH₃COOH) to form water and acetate ion (CH₃COO^-).

300

Which of the following combinations is NOT a buffer solution?

NH₃ and (NH₄)₂SO4

HBr and KBr

NH₃ and NH₄Br

CH₃COOH and NaCH₃COO

HCN and NaCN

HBr and KBr

Titrations

100

For a strong acid and strong base titration, what is the pH at the equivalence point?

7

200

When does the pKa = pH at the mid-equivalence point?

For strong acid/weak base or strong base/weak acid titrations.