AP Chemistry Unit 8

Buffer

100

What is the conjugate of HClO?

ClO^-

200

pH = pKa

What is the pH at the half equivilance point?

300

A buffer is made of HF and NaF. What is the chemical reaction that occurs when NaOH is added?

HF + OH^- --> H₂O + F^-

400

Determine the pH of a 10.0 mL buffer made of 0.10 mol of HF and 0.10 mol of NaF AFTER 0.02 moles of HCl is added. The Ka of HF is 1.8 x 10^-5

4.56

500

A solution containing HNO₂ and NaNO₂ has a pH of 3.20. Is the [HNO₂] <, >, or = [NaNO₂]? Explain how you know. The K_a of HNO₂ is 4.0 x 10^-4.

[HNO₂] > [NaNO₂] because the pH is more acidic than the pKa.

Strong

100

pH of 0.001 M HI

3

200

pH of 0.00005 M Ca(OH)₂

10

300

Name ALL 6 strong acids.

HCl, HI, HBr, HNO₃, HClO₄, H₂SO₄

400

The concentration of a solution of HNO₃ has a pH of 2.50. 

0.0032 M

500

The pH of a solution containing 40.0 mL of 0.20 M LiOH and 60.0 mL of 0.10 HClO₄

12.30

Titration

100

The pH at the equivalence point of a strong acid - strong base titration.

7

200

The point on a titration curve used to find the Ka of a weak acid or weak base.

Half equivalence point.

300

25.0 mL of weak acid was titrated with 0.01 M NaOH. The equivalence point was reached after 30.0 mL of NaOH was added. What is the initial concentration of the weak acid?

0.012 M

400

What is the Ka of the acid (see titration curve).

Between 1.1 x 10^-4 and 2.0 x 10^-4

500

HF was titrated with NaOH according to the titration curve. Draw a particle diagram that shows the relative concentrations of Na⁺, HF, and F^- present in solution after 10.0 mL of NaOH has been added.

[Na⁺] = [F^-] < [HF]

Random

100

Write the equilibrium expression for the reaction of HClO₂ in water. Include K_a or K_b

K_a = [H₃O⁺][ClO₂^-]/[HClO₂]

200

Fill in the blanks to Mrs. Lehmann's rap.

You mix the acid with the _____. You get ____ now find pH. If its weak, there'll be a ____. Find the excess, use ____. More strong? Thats so easy __________ see. More weak? Don't suffer Use the __________ it's a _____!

You mix the acid with the base. You get water now find pH. If its weak, there'll be a K. Find the excess, use BCA. More strong? That's so easy, -log the diluted molarity see. More weak? Don't suffer. Use the H-H equation it's a buffer!

300

What is the pH of a 0.50 M solution of NH₃? K_b = 1.8 x 10^-5

11.48

400

Molarity of LiOH when 0.532 g are dissolved in 300.0 mL of water (sig figs matter!)

0.0740 M

500

50.0 mL of 0.10 M CH₃NH₂ reacts with 50.0 mL of 0.10 M HC₂H₃O₂. Is the solution acidic, basic, or neutral? The K_b for CH₃NH₂ is 4.4 x 10^-4 and the K_a for HC₂H₃O₂ is 1.8 x 10^-5

Basic (base is stronger than the acid due to K_b > K_a) and there are equal amounts of both.