Chemistry Reference
In-Depth Information
Example 2
Determine the pH and the pOH of a 0.01 M solution of NaOH, a
strong base.
The key to this problem is that we are dealing with a strong base. The
fact that it is strong means that the NaOH will ionize completely, releasing
enough ions so that the concentration of hydroxide ions will be 0.01 M.
Given: [OH-] = 0.01 M
Find:
A. pOH
B. pH
Answer:
A. pOH = -log(0.01) = 2
B. pH = 14 - pOH = 14 - 2 = 12
Lesson 9-5 Review
1.
The ionization constants for four bases are shown here. Select the
constant that represents the strongest base.
a) K
b
= 1.0 × 10
-2
c) K
b
= 1.0 × 10
-5
b) K
b
= 1.0 × 10
-3
d) K
b
= 1.0 × 10
-7
2.
The ionization constants for four acids are shown here. Select the
constant that represents the strongest acid.
a) K
a
= 1.0 × 10
-9
c) K
a
= 1.0 × 10
-5
b) K
a
= 1.0 × 10
-6
d) K
a
= 1.0 × 10
-2
3.
The ionization constants for four bases are shown here. Which of the
bases represented would have the strongest conjugate acid?
a) K
b
= 1.0 × 10
-6
c) K
b
= 1.0 × 10
-3
b) K
b
= 1.0 × 10
-4
d) K
b
= 1.0 × 10
-1
Lesson 9-6: Acid-Base Titrations
One common laboratory activity, which makes use of the information
that we have covered in this chapter, is an acid-base titration reaction. A
titration reaction is a neutralization reaction carried out using a solution
with a known concentration (called a standard solution), in order to find
the concentration of an unknown solution. By determining the volume of
the standard solution required to neutralize a specific volume of the un-
known solution, we can mathematically determine the concentration of
the unknown. An indicator is used to signal the time when neutralization
occurs, which is called the end point or the equivalence point of the titration.
