Name: _____________________________________
Worksheet – Acids, Bases, and pH
1. Define the following terms:
Arrhenius Acid – releases H+ into solution
Arrhenius Base – releases OH- into solution
Bronsted Lowry Acid – proton (H+) donor
Bronsted Lowry Base – proton (H+) acceptor
2. Identify the acid, base, conjugate acid, and conjugate base in each of the following reactions.
HNO2 + H2O ⇌ NO2- + H3O+
acid
base
conj
base
conj
acid
HCl + NH3 ⇌ NH4+ + Clacid
base
conj
acid
conj
base
HPO4-2 + NH4+ ⇌ H2PO4- + NH3
CH3CO2H + H2O ⇌ CH3CO2- + H3O+
base
acid
acid
conj
acid
conj
base
base
conj
base
conj
acid
3. A monoprotic acid contains __1____ protons. A diprotic acid contains __2____ protons. A triprotic acid contains
__3___ protons.
4. Define and give an example of each of the following.
Strong acid – completely ionizes in solution – releases all of H+ into solution - HCl
Weak acid – partially ionizes in solution – only releases some of H+ into solution – CH3CO2H
Strong base – directly releases OH- into solution - NaOH
Weak base – indirectly releases OH- into solution – NH3
5. In a neutral solution, the pH is ___7___. In an acidic solution the pH is _<7____. In a basic solution the pH is _>7__.
6. Complete the following table.
pH
[H+]
[OH-]
[H+] > or < or = [OH-]
7
10-7
10-7
=
5
10-5
10-9
>
11
10-11
10-3
<
10
10-10
10-4
<
2
10-2
10-12
>
3
10-3
10-11
>
7. Briefly describe the purpose of a buffer.
Maintain the pH when an acid or base is added to the solution
8. Briefly explain why weak acids and weak bases are used to make buffers.
When an acid or a base is added to a buffered solution, a H+ or OH- is removed due to the neutralization reaction that
occurs. When a H+ or OH- is removed it must be replaced or the pH will change. A weak acid or weak base has a
“reserve” that can be used to replace the H+ or OH-.