Acids and Bases Review Guide Answers
1. What are 3 properties of acids? What are 3 properties of bases?
See notes…any are GOOD 
2. What is the purpose of an indicator? Give an example.
To identify a substance as an acid or base. Ex: Phenolphthalein turns pink in a base, litmus paper
changes color according to the type of substance (red is acid/blue is base)
3. What does a neutralization reaction produce?
Acid + Base  Salt + H2O
4. What is an Arrhenius acid? What is an Arrhenius base?
Arrhenius acid – produces H+ ions when put in water
Arrhenius base – produces OH- ions when put in water
5. Are the following acidic, basic, or neutral?
a) pH = 4 acidic
b) pOH = 9 acidic (pH = 5)
c) pH = 10 basic
d) pOH = 2 basic (pH = 12)
6. If the H+ concentration is 8.6 x 10-3 M, what is the pH of the solution?
pH = - log [H+]
pH = - log (8.6 x 10-3)
pH = 2.1
7. If the [OH-] in a solution is 5.2 x 10-5 M, what is the pH?
pOH = - log [OH-]
pH + pOH = 14
-5
pOH = - log (5.2 x 10 )
pH + 4.284 = 14
pOH = 4.284
pH = 9.7
8. If the pH is 2.5, what is the [H+]?
pH = - log [H+]
2.5 = - log [H+]
10-2.5 = [H+]
[H+] = 3.2 X 10-3 M
9. If the pOH is 2.5, what is the [OH-]?
pOH = - log [OH-]
2.5 = - log [OH-]
10-2.5 = [OH-]
[OH-] = 3.2 X 10-3 M
10. If the OH concentration is 6.5 x 10-5 M, what is the [H+]?
pOH = - log [OH-]
pH + pOH = 14
pOH = - log (6.5 x 10-5)
pH + 4.187 = 14
pOH = 4.187
pH = 9.813
pH = - log [H+]
9.813 = - log [H+]
10-9.813 = [H+]
[H+] = 1.5 x 10-10 M
11. What are the strong acids?
HCl, HBr, HI, HNO3, H2SO4, HClO3, HClO4
12. What are the strong bases?
All the group 1A metal bonded to hydroxide
Group 2A metal (from calcium down) bonded to hydroxide
13. What is the difference between strong acids/bases and weak acids/bases?
Strong acids/bases complete dissociate into their ions and weak acids/bases only partially
dissociate.
14. What is the purpose of a titration?
To determine the volume or molarity of an acid or a base that is unknown.
15. It takes 12.8 mL of 0.25M NaOH to turn 22.0 mL of HCl pink. What is the molarity of the HCl?
1)
NaOH + HCl  NaCl + H2O
2)
M 
0.25 
x mol
=> 0.0032 mol NaOH
0.0128 L
3)
0.0032 mol NaOH x
1 mol HCl
= 0.0032 mol HCl
1 mol NaOH
4)
M 
mol
L
mol
L
M 
0.0032
= 0.15 M HCl
0.0220
16. A 25mL sample of H2SO4 was exactly neutralized by 32 mL of 1.3 M KOH. What is the molarity of
the H2SO4?
1)
H2SO4 + 2KOH  2H2O + K2SO4
2)
M 
3)
0.0416 mol KOH x
4)
M 
mol
L
mol
L
1.3 
M 
x mol
=> 0.0416 mol KOH
0.032 L
1 mol H 2 SO4
= 0.0208 mol H2SO4
2 mol KOH
0.0208
= 0.83 M H2SO4
0.025
17. How much 2.0 M NaOH is necessary to exactly neutralize 30 mL of 1.8 M HNO3?
1)
HNO3 + NaOH  H2O + NaNO3
2)
M 
mol
L
1.8 
x mol
=> 0.054 mol HNO3
0.03 L
3)
0.054 mol HNO3 x
4)
M 
mol
L
2.0 
1 mol NaOH
= 0.054 mol NaOH
1 mol HNO3
0.054
xL
= 0.03 L NaOH
18. How much of 1.2 M H3PO4 is necessary to neutralize 34.0 mL of 0.8 M Ca(OH)2?
1)
2H3PO4 + 3Ca(OH)2  6H2O + Ca3(PO4)2
2)
M 
3)
0.0272 mol Ca(OH)2 x
4)
M 
mol
L
mol
L
0.8 
1.2 
x mol
0.034 L
2 mol H 3 PO4
3 mol Ca(OH) 2
= 0.0181 mol H3PO4
0.0181
= 0.02 L H3PO4
xL
19. What is a standard solution?
The solution in a titration that you know the concentration and volume of. It is your “known”
solution.
20. What is a binary acid and how can you identify one by its name?
A binary acid is composed on ONLY 2 elements. You can identify it by name because it starts with
the prefix, hydro
21. What is an oxyacid and how can you identify one by its name?
An oxyacid is composed on 3 or more elements (one molecule is a polyatomic ion). By name it
DOESN”T start with hydro.
22. If red litmus paper turns blue, is the substance an acid or base? Base
23. If blue litmus paper turns red, is the substance an acid or base? Acid
24. If blue litmus paper stays blue, and red stays red, what is the substance? Neutral
Write out the formula or name for the following:
30. Carbonic acid__H2CO3____________
25. HClO3__Chloric acid____________
26. HBr__Hydrobromic acid_________
31. Hydrobromic acid__HBr__________
27. HNO2__Nitrous acid____________
32. Dichromic acid____H2Cr2O7______
28. H2SO3__Sulfous acid____________
33. Hypoiodous acid___HIO_____________
29. HI___Hydroiodic acid___________
34. Bromous acid____HBrO2_________
36. Hydrosufuric acid___H2S______
35. Hydrochloric acid___HCl_________
37. SAME QUESTION AS NUMBER 1
38. What is the pH scale used for? To determine how acidic and basic a solution is
39. Draw the pH scale and label where it is acidic, basic, and neutral.
7
0
Neutral
Acidic
14
Basic
40. How many grams of NaOH must be dissolved in to a 2.0 L solution to make it have a concentration
of 1.21M?
M 
mol
L
1.21 =
2.42𝑚𝑜𝑙 𝑁𝑎𝑂𝐻 ×
𝑚𝑜𝑙
1.21(2.0) = 𝑚𝑜𝑙
2.0
40.0𝑔 𝑁𝑎𝑂𝐻
1𝑚𝑜𝑙 𝑁𝑎𝑂𝐻
𝑚𝑜𝑙 = 2.42
= 96.8−→ 97𝑔 𝑁𝑎𝑂𝐻
41. What is the molality of a solution containing 58.4 g of NH3 dissolved in 658 g of solution?
58.4𝑔 𝑁𝐻3 ×
𝑚=
1 𝑚𝑜𝑙 𝑁𝐻3
17𝑔 𝑁𝐻3
= 3.4353 𝑚𝑜𝑙 𝑁𝐻3
𝑚𝑜𝑙
3.4353
=
= 5.2208−→ 5.22𝑚 𝑁𝐻3
𝑘𝑔
. 658
42. A gas mixture contains 42.84 g of steam (H2O), 3.58 g of hydrogen and 9.29 g of nitrogen. What is
the mole fraction of steam?
42.84 𝑔 𝐻2 𝑂 ×
1 𝑚𝑜𝑙 𝐻2 𝑂
18.0𝑔 𝐻2 𝑂
3.58 g H2 ×
1 mol H2
9.29 𝑔 𝑁2 ×
1 𝑚𝑜𝑙 𝑁2
2.0 g H2
28 𝑔 𝑁2
= 2.38 𝑚𝑜𝑙 𝐻2 𝑂
2.38 + 1.79 + .33179 = 4.50179
= 1.79 mol H2
𝑚𝑜𝑙𝑒 𝑓𝑟𝑎𝑐𝑡𝑖𝑜𝑛 =
= .33179 𝑚𝑜𝑙 𝑁2
𝑚𝑜𝑙𝑒 𝑓𝑟𝑎𝑐𝑡𝑖𝑜𝑛 =
𝑚𝑜𝑙𝑒𝑠 𝑜𝑓 𝑠𝑢𝑏𝑠𝑡𝑎𝑛𝑐𝑒
𝑡𝑜𝑡𝑎𝑙 𝑚𝑜𝑙𝑒𝑠
2.38
4.50179
𝑚𝑜𝑙𝑒 𝑓𝑟𝑎𝑐𝑡𝑖𝑜𝑛 = 0.529