Acids and Bases ANSWER SHEET
Name:________________________ PD.__________
Date:_________________
1. Properties of acids and bases: Label the following acid, base, or both.
- taste sour_________ A
- has a pH greater than 7 _________ B
- reacts with hydrogen gas on active metals (e.g.: Mg) _________ A
- conducts electricity _________ A and B
- feels slippery or soapy_________ B
- neutralizes bases_________ A
- neutralizes acids_________ B
- taste bitter ________ B
- turns red litmus paper blue in color_________ B
- turns blue litmus paper red in color _________ A
- has a pH less than 7 _________ A
2. Writing acid-base reactions in aqueous solutions:
Notable points to remember :
-The properties of an acid are neutralized by the addition of a base, and vice versa.
- Arrhenius proposed that an acid is a substance that produces hydrogen ions (H + , also called protons) in aqueous solution, and a base is a substance that produces hydroxide ions (OH
–
) in aqueous solution
-all acids and bases are electrolytes undergoing dissociation in aqueous solution.
-Arrhenius explained neutralization as the combination of H + ions and OH
–
ions to form water.
H + (aq) + OH
–
(aq) H
2
O(l)
In the Brønsted– Lowry theory, an acid donates a proton and the base accepts it.
-. Lewis ' theory used electrons instead of proton transfer and specifically stated that an acid is a species that accepts an electron pair while a base donates an electron pair.
3. Write a balanced net ionic equation for each of the following acid-base reactions in water: i. butyric acid (HC4H7O2, a weak acid) with potassium hydroxide (KOH, a strong base)
HC4H7O2 (aq) + OH(aq) ----->C4H7O2(aq) + HOH ii. ammonia (NH3, a weak base) with hydrobromic acid (HBr, a strong acid)
NH3 (aq) + H 1+ (aq)--------> NH4 1+ (aq) iii. nitric acid (HNO3, a strong acid) with lithium hydroxide (LiOH, a strong base)
H 1+ (aq) + OH1- (aq)-----> HOH
4. Identify which characteristic falls under Arrhenius, bronsted lowry, or lewis theories of acids and bases.
Hint: Arrhenius (producing different ions) Bronsted Lowry (proton) lewis (electrons)
Bronsted lowry : An acid is a proton (hydrogen ion) donor.______________________________

Lewis : An acid is an electron pair acceptor__________________________________________
Arrhenius : Acids are substances which produce hydrogen ions in solution_________________
Bronsted lowry: A base is a proton (hydrogen ion) acceptor._____________________________
-.
Arrhenius : Bases are substances which produce hydroxide ions in solution_________________
Lewis: A base is an electron pair donor._____________________________________________
5. Given that [H
3
O + ] = 4.5 x 10 -5 M, calculate [OH ]. remember [H
3
O + ]·[OH ] = K w
and K w is always equal to 1.0 x 10 -14 calculate [OH ] given that [H
3
O + ] = 4.5 x 10 -5 M. Starting with the water constant equation
[H
3
O + ]·[OH ] = K w
, we can figure that [OH ] = K w
/[H
3
O + ]. Then, substitute the known values for K w and [H
3
O + ] to get that [OH ] is equal to 1.0 x 10 -14 divided by 4.5 x 10 -5 . That comes out to be 2.2 x 10 -10 M for the concentration of hydroxide ion.
6. Calculate PH and POH for each equation (pH = - log [H
3
O + ]) (pOH = - log [OH ])
Find the pH of a 0.0025 M HCl solution
PH = - log (0.0025) = - ( - 2.60) = 2.60 (PH)
PH +POH= 14 so 14-2.6 =11.4 (POH)
7. What is the pOH of a solution that has a hydroxide ion concentration of 4.82 x 10 -5 M pOH = - log [4.82 x 10 -5 ] = 4.32
8. What is the purpose of titration?
The purpose of titrating is to determine the concentration of an unknown acid or base.
9. A 15.0 mL sample of an H
2
SO
4
is titrated with 50.5 mL of 0.200M KOH. What is the concentration of the unknown acid?
0.200M KOH=(x/.0505 L KOH)=.0101 mol KOH
.0101 mol KOH(1 mol H
2
SO
4
/2 mol KOH)=.00505 mol H
2
SO
4
.00505 mol H
2
SO
4
/.015 L H
2
SO
4
=.337M H
2
SO
4
10. What is the concentration of a 10 mL sample of HCl if 30.2 mL of 0.120M NaOH is needed to titrate it?

.120M NaOH=(x/.0302L)=.0036 mol NaOH
.0036 mol NaOH(1 mol HCl/1 mol NaOH)=.0036 mol HCl
.0036 mol HCl/.010 L HCl= .36 M HCl
11. Fill in the blanks:
● Binary acids are made up of two elements. The first element in a binary acid is hydrogen .
○ Naming: hydro__(root word of second element)__ic acid
● Oxyacids are made up of more than two elements.
○ Naming: NO PREFIX. Change the ending of the polyatomic ion’s name and add the word “acid”;
-ate becomes -ic and -ite becomes -ous
12. Name the following acids: hydrofluoric acid HF
H
2
CO
3 carbonic acid
HC
2
H
3
O
2 acetic acid