Download Acids and pH

Logarithms
Logarithms
The logarithm of a number is
the number of times
10 must be multiplied by itself
to equal that number.
Logarithms
1000 = 10 x 10 x 10
log 1000 = 3
Logarithms
To find the logarithm of a
number, count the zeroes.
If the number is in
scientific notation,
look at the exponent.
Logarithms
1 = 1 x 100
1
10 = 1 x 10
2
100 = 1 x 10
0.1 = 1 x 10-1
0.01 = 1 x 10-2
log 1 = 0
log 10 = 1
log 100 = 2
log 0.1 = -1
log 0.01 = -2
Logarithms
You can multiply two numbers by
adding their logarithms.
Logarithms
You can multiply two numbers by
adding their logarithms.
100 x 1000 = 100,000
Logarithms
You can multiply two numbers by
adding their logarithms.
100 x 1000 = 100,000
2+3=5
Logarithms
You can multiply two numbers by
adding their logarithms.
1x
8
10
= 100,000,000
Logarithms
You can multiply two numbers by
adding their logarithms.
1x
8
10
= 100,000,000
0+8=8
Logarithms
You can multiply two numbers by
adding their logarithms.
2x
8
10
= 200,000,000
?+8= ?
Logarithms
So what’s the logarithm of 2?
You have to look it up.
2x
8
10
= 200,000,000
?+8= ?
Logarithms
So what’s the logarithm of 2?
You have to look it up.
8
10
2x
= 200,000,000
0.301 + 8 = 8.301
Logarithms
What if the number is small
instead of big?
Logarithms
What if the number is small
instead of big?
0.0003 = 3 x 10-4
Logarithms
What if the number is small
instead of big?
0.0003 = 3 x 10-4
log 0.0003 = log 3 + log 10-4
Logarithms
What if the number is small
instead of big?
0.0003 = 3 x 10-4
log 0.0003 = log 3 + log 10-4
= 0.477 – 4
Logarithms
What if the number is small
instead of big?
0.0003 = 3 x 10-4
log 0.0003 = log 3 + log 10-4
= 0.477 – 4
= -3.523
Logarithms
Try a few!
Logarithms
log
3
10
=
Logarithms
log
3
10
=3
Logarithms
log
8
10
=
Logarithms
log
8
10
=8
Logarithms
log
-10
10
=
Logarithms
log
-10
10
= -10
Logarithms
log 2 =
Logarithms
log 2 = 0.301
Logarithms
log 5.8 =
Logarithms
log 5.8 = 0.763
Logarithms
log 9.2 =
Logarithms
log 9.2 = 0.963
Logarithms
log 4 x
12
10
=
Logarithms
log 4 x
12
10
= 0.602 + 12
Logarithms
log 4 x
12
10
= 0.602 + 12
= 12.602
Logarithms
log 8.3 x
5
10
=
Logarithms
log 8.3 x
5
10
= 0.919 + 5
Logarithms
log 8.3 x
5
10
= 0.919 + 5
= 5.919
Logarithms
log 7.1 x
-3
10
=
Logarithms
log 7.1 x
-3
10
= 0.851 - 3
Logarithms
log 7.1 x
-3
10
= 0.851 - 3
= -2.149
Logarithms
log 4.8 x
-11
10
=
Logarithms
log 4.8 x
-11
10
= 0.681- 11
Logarithms
log 4.8 x
-11
10
= 0.681- 11
= -10.319
pH
pH = -log
+
[H ]
[OH ]
pOH = -log
pH + pOH = 14
+
[H ]
= 0.0035
What is the pH?
+
[H ]
= 0.0035
0.0035 = 3.5 x
-3
10
+
[H ]
= 0.0035
-3
10
0.0035 = 3.5 x
-3
log 0.0035 = log 3.5 + log 10
+
[H ]
= 0.0035
-3
10
0.0035 = 3.5 x
-3
log 0.0035 = log 3.5 + log 10
= 0.544 – 3
+
[H ]
= 0.0035
-3
10
0.0035 = 3.5 x
-3
log 0.0035 = log 3.5 + log 10
= 0.544 – 3
= –2.456
+
[H ]
= 0.0035
-3
10
0.0035 = 3.5 x
-3
log 0.0035 = log 3.5 + log 10
= 0.544 – 3
= –2.456
pH = 2.456
pH = 6.13
What is the
+
[H ]?
pH = 6.13
–pH = –6.13
pH = 6.13
–pH = –6.13
= 0.87 – 7
pH = 6.13
–pH = –6.13
= 0.87 – 7
+
-7
[H ] = 7.4 x 10
pH = 8.7
What is the pOH?
pH = 8.7
pOH = 14 - pH
pH = 8.7
pOH = 14 - pH
= 14 – 8.7
pH = 8.7
pOH = 14 - pH
= 14 – 8.7
= 5.3
pH = 8.7
pOH = 14 - pH
= 14 – 8.7
= 5.3
The solution is acidic.
Always Remember:
Always Remember:
The molarity of a solution
refers to how many moles
per liter it has.
Always Remember:
The molarity of a solution
refers to how many moles
per liter it has.
1.0 M = 1.0 mol/L
Always Remember:
A strong acid or base
dissociates completely in
water.
Always Remember:
A strong acid or base
dissociates completely in
water.
1.0 M HCl = 1.0 M
+
H
Always Remember:
A strong acid or base
dissociates completely in
water.
+
H
1.0 M HCl = 1.0 M
1.0 M NaOH = 1.0 M OH
Always Remember:
Polyprotic acids have more
than one hydrogen.
Always Remember:
Polyprotic acids have more
than one hydrogen.
1.0 M H2SO4 = 2.0 M
+
H
.
Suggested Homework
Page 609 # 18
Page 611 # 19
Page 612 # 20
Daily Quiz – pH and logarithms
Daily Quiz – pH and logarithms
1. What is true of [H+] and [OH-]?
a.
=
b. [H+] x [OH-] = 1 x 10-7
+
-7
c. [H ] ÷ [OH ] = 1 x 10
d. [H+] x [OH-] = 1 x 10-14
+
-14
e. [H ] ÷ [OH ] = 1 x 10
+
[H ]
[OH ]
Daily Quiz – pH and logarithms
2. In a neutral solution, pH =
a. 0
b. 0.5
c. 1
d. 7
e. 14
Daily Quiz – pH and logarithms
3. 1 x
a.
b.
c.
d.
-5
10
=?
5
100,000
0.000,01
0.000,001
Daily Quiz – pH and logarithms
4. Which number is bigger?
a. 1 x 10-2
-6
b. 1 x 10
Daily Quiz
[H+], [OH-], and pH
1. You have a 1.0M solution of HI
(a strong acid).
What is the pH?
a. 0.0
b. 1.0
c. 10.0
d. 13.0
Daily Quiz
[H+] & [OH-] to pH
2. You have a 1.0M solution of
HNO3 (a strong acid).
What is the pH?
a. 0.7
b. 1.3
c. 2.0
d. 5.0
Daily Quiz
[H+], [OH-], and pH
3. You have a 1.0M solution of
KOH (a strong base).
What is the pH?
a. 0.0
b. 1.0
c. 7.0
d. 14.0
Daily Quiz
[H+], [OH-], and pH
4. You have a 10-5M solution of
Mg(OH)2 (a strong base).
What is the pH?
a. 4.32
b. 4.62
c. 9.38
d. 9.68
Daily Quiz – pH and logarithms
1. What is true of [H+] and [OH-]?
a.
=
b. [H+] x [OH-] = 1 x 10-7
+
-7
c. [H ] ÷ [OH ] = 1 x 10
d. [H+] x [OH-] = 1 x 10-14
+
-14
e. [H ] ÷ [OH ] = 1 x 10
+
[H ]
[OH ]
Daily Quiz – pH and logarithms
1. What is true of [H+] and [OH-]?
a.
=
b. [H+] x [OH-] = 1 x 10-7
+
-7
c. [H ] ÷ [OH ] = 1 x 10
d. [H+] x [OH-] = 1 x 10-14
+
-14
e. [H ] ÷ [OH ] = 1 x 10
+
[H ]
[OH ]
Daily Quiz – pH and logarithms
2. In a neutral solution, pH =
a. 0
b. 0.5
c. 1
d. 7
e. 14
Daily Quiz – pH and logarithms
2. In a neutral solution, pH =
a. 0
b. 0.5
c. 1
d. 7
e. 14
Daily Quiz – pH and logarithms
3. 1 x
a.
b.
c.
d.
-5
10
=?
5
100,000
0.000,01
0.000,001
Daily Quiz – pH and logarithms
3. 1 x
a.
b.
c.
d.
-5
10
=?
5
100,000
0.000,01
0.000,001
Daily Quiz – pH and logarithms
4. Which number is bigger?
a. 1 x 10-2
-6
b. 1 x 10
Daily Quiz – pH and logarithms
4. Which number is bigger?
a. 1 x 10-2
-6
b. 1 x 10
Daily Quiz
[H+], [OH-], and pH
1. You have a 1.0M solution of HI
(a strong acid).
What is the pH?
a. 0.0
b. 1.0
c. 10.0
d. 13.0
Daily Quiz
[H+], [OH-], and pH
1. You have a 1.0M solution of HI
(a strong acid).
What is the pH?
a. 0.0
b. 1.0
c. 10.0
d. 13.0
Daily Quiz
[H+], [OH-], and pH
1. You have a 1.0M solution of HI
(a strong acid).
What is the pH?
a. 0.0
b. 1.0
c. 10.0
d. 13.0
Why?
Daily Quiz
[H+], [OH-], and pH
1.0M HI
+
0
[H ] = 1.0 x 10
+
log[H ] = 0.00 + 0
pH = 0.00
Daily Quiz
[H+] & [OH-] to pH
2. You have a 1.0M solution of
HNO3 (a strong acid).
What is the pH?
a. 0.7
b. 1.3
c. 2.0
d. 5.0
Daily Quiz
[H+] & [OH-] to pH
2. You have a 1.0M solution of
HNO3 (a strong acid).
What is the pH?
a. 0.7
b. 1.3
c. 2.0
d. 5.0
Daily Quiz
[H+] & [OH-] to pH
2. You have a 1.0M solution of
HNO3 (a strong acid).
What is the pH?
a. 0.7
b. 1.3
c. 2.0
d. 5.0
Why?
Daily Quiz
[H+], [OH-], and pH
0.050M HNO3
+
-2
[H ] = 5.0 x 10
+
log[H ] = 0.70 – 2
pH = 1.30
Daily Quiz
[H+], [OH-], and pH
3. You have a 1.0M solution of
KOH (a strong base).
What is the pH?
a. 0.0
b. 1.0
c. 7.0
d. 14.0
Daily Quiz
[H+], [OH-], and pH
3. You have a 1.0M solution of
KOH (a strong base).
What is the pH?
a. 0.0
b. 1.0
c. 7.0
d. 14.0
Daily Quiz
[H+], [OH-], and pH
3. You have a 1.0M solution of
KOH (a strong base).
What is the pH?
a. 0.0
b. 1.0
c. 7.0
d. 14.0
Why?
Daily Quiz
[H+], [OH-], and pH
1.0M KOH
0
[OH ] = 1.0 x 10
log[OH ] = 0.00 + 0
pOH = 0.00
pH = 14.00
Daily Quiz
[H+], [OH-], and pH
4. You have a 10-5M solution of
Mg(OH)2 (a strong base).
What is the pH?
a. 4.32
b. 4.62
c. 9.38
d. 9.68
Daily Quiz
[H+], [OH-], and pH
4. You have a 10-5M solution of
Mg(OH)2 (a strong base).
What is the pH?
a. 4.32
b. 4.62
c. 9.38
d. 9.68
Daily Quiz
[H+], [OH-], and pH
4. You have a 10-5M solution of
Mg(OH)2 (a strong base).
What is the pH?
a. 4.32
b. 4.62
c. 9.38
d. 9.68
Why?
Daily Quiz
[H+], [OH-], and pH
-5
10 M
2.4 x
Mg(OH)2
-5
[OH ] = (2.4 x 10 ) x 2
log[OH ] = 0.68 – 5
pOH = 4.32
pH = 9.68
.
Suggested Homework
Page 609 # 18
Page 611 # 19
Page 612 # 20
.