Teacher Notes
Name
Key
Class
Date
Acids and Bases
1. Compare properties of acids and bases. Circle any properties that they have in common.
ACIDS
BASES
Taste
Sour
Bitter
Feel
------
Slippery
H2 given off
--------
Electrolyte
yes
yes
Indicator – Litmus
Red
Blue
Colorless
Pink
Reaction/Metals
Indicator-Phenolphthalein
2. What is the formula for the hydronium ion? H3O+
How is it related to H+?
It is a hydrated H+ (H2O + H+)
3. How does a chemist define each of the following terms?
a. Weak
Little dissociation (weak electrolyte)
b. Strong
Almost 100% dissociation (strong electrolyte)
c. Dilute
Little solute, lots of solvent
d. Concentrated
Lots of solute
4. Give an example of each of the following.
a.
A weak acid
b. A weak base
CH3COOH
c. A strong acid
HCl, HNO3
NH3
d. A strong base
NaOH, KOH
5. What is neutralization?
Reaction between acid and base to form salt + H2O
6. What are the products if equal amounts of an acid and a base react?
7. Is acid/base neutralization endothermic or exothermic?
8. Define and give two examples of polyprotic acids.
H2SO4, H2CO3, H3PO4
A salt and water
exothermic
Acids that can donate more than one proton.
Teacher Notes
9. What is a titration?
The measured addition of acid and base to neutralize each other.
10. What laboratory glassware is used in a titration?
Buret
11. What is true about the amount of H+ (acid) and OH- (base) in a solution at the equivalence point of a
titration?
They are equal.
12. How can we know that the endpoint in a titration has been reached?
By observing the color
change of an indicator or by measuring a sharp change in pH with a pH meter.
13. In an acid/base neutralization, the cation of the base and the anion of the acid combine to make a salt.
What acid and base must have combined to make each of the following salts?
NaCl
NaOH, HCl
NH4Cl
NH4OH, HCl
Na2SO4
NaOH,_H2SO4
K3PO4
KOH, H3PO4
KNO3
KOH, HNO3
Ca(NO3)2
Ca(OH)2, HNO3
14. At the equivalence point, moles of acid in the solution = moles of base. For monoprotic acids and
bases, we can express this mathematically as
MaVa = MbVb
a. 38.0 mL of 0.10M HCl is needed to neutralize 25.0 mL to NH4OH. What is the molarity of the
ammonium hydroxide?
Mb = MaVa
Vb
Mb = (0.10 M)(38.0 mL)
(25.0 mL)
Mb = 0.15 M NH4OH
b. 29.5mL of 0.15M NaOH neutralizes 25.0mL of HNO3. What is the molarity of the acid?
Ma = MbVb
Va
Ma = (0.15 M)(29.5 mL)
(25.0 mL)
Ma = 0.18 M HNO3
c. 30.0mL of 0.20M HCl will be neutralized with 0.50M NaOH. What volume of the base is
needed?
Vb = MaVa
Mb
Vb = (0.20 M) ( 30.0 mL)
(0.50 M)
Vb = 12 mL of NaOH