Acid Base Review Station Activity
• List the strong acids and strong bases
• What happens if the following substances are
in solution (equilibrium, reaction, buffer)?
– weak base
– weak acid and a strong base
– Acid and base
– Weak acid and its conjugate base
– Weak acid
– Strong acid and strong base
1. Fifty mL of 5 M nitric acid needs to be diluted
to 1 M. Water is added until this
concentration is met. What is the final
volume? What is the initial and final pH of
the nitric acid?
2. If 50.0 grams of solid salicylic acid (HC7H5O3,
Ka=1.07x10-3) are dissolved in 500mL of water,
what is the pH?
• Does substance A depict a strong
or a weak acid? Explain.
• Compare the strengths of A and B.
Justify your choice.
• Which would have a larger Ka?
How do you know?
A
B
Strengths of weak acids and weak bases
Acid
Ka at 298 K
HOCl
2.9 x 10-8
2.4 x 10
• Answer the following questions: HOBr
1. Which of the two acids is stronger, HOCl or HOBr?
Justify in terms of Ka.
2. Hypoiodous acid has the formula HOI. Predict
whether HOI is a stronger acid or a weaker acid
than the acid that you identified in part 1. Justify
your prediction in terms of chemical bonding.
3. Which of the two conjugate bases, OCl-1 or OBr-1, is
stronger? Justify your answer.
-9
Write balanced, net-ionic equations for the neutralization
reactions below. Assume that all species are in aqueous
solution.
1. Potassium hydroxide and hydroiodic acid
2. Ascorbic acid (H2C6H6O6) and barium hydroxide (assume
ascorbic acid is monoprotic  it releases only one hydrogen
ion)
3. Hydrocyanic acid (HCN) and silicate (SiO3-2)
4. Ammonia and sulfuric acid (while this acid is diprotic, the
first proton is released much easier than the second, so
write the reaction when just one proton reacts)
A. Underneath each substance write an ‘A’ or a ‘B’ to indicate
whether it is an acid or a base. Do this under the reactants
and the products.
B. Define monoprotic and diprotic. Give an example of a
triprotic acid. (Diprotic and triprotic acids are called polyprotic acids)
1. When 20 mL of 0.55 M acetic acid (Ka=1.8E-5)
reacts with 45 mL of calcium hydroxide, the
indicator changes colors indicating that the
___________ __________ has been reached.
2. What is the concentration of calcium
hydroxide?
3. What is the pH of the solution at the __ __?
A) Write the equilibrium expression for the
reaction of methylamine (CH3NH2) with water.
B) Determine the Kb of a 0.845 M solution of
methylamine with a pH of 12.284.
C) Is methylamine an acid or a base? Is it weak
or strong? How do you know?
• Phosphoric acid forms 3 separate equilibrium
reactions; in each reaction just 1 proton (H+) pops
off
– Write the three equilibrium reactions
• Ka1 is the equilibrium constant for the first proton
removal, Ka2 is for the second, etc.
Formula
Ka1
Ka2
Ka3
H3PO4
7.5 x10-3
6.2 x10-8
4.8 x10-13
– How do these values compare to each other?
• The following ions are in order. Do they go in
order of increasing or decreasing concentration in
a solution of phosphoric acid? Justify your
answer.
– H3PO4, H2PO41-, HPO42-, PO43-