yesterday’s homework. the concentration of either the h + ion or the oh - ion is given for three...
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Yesterday’s Homework
Yesterday’s Homework
The concentration of either the H+ ion or the OH- ion is given for three aqueous solutions at 298oK. For each solution, calculate [H+] or [OH-]. State whether the solution is acidic, basic, or neutral.
Yesterday’s Homework
If this wasn’t easy, you’re doing it wrong.
Yesterday’s Homework
[H+] = 1.0 x 10-13M
Yesterday’s Homework
[H+] = 1.0 x 10-13M[OH-] = 1.0 x 10-1M
Yesterday’s Homework
[H+] = 1.0 x 10-13M[OH-] = 1.0 x 10-1M
basic
Yesterday’s Homework
[OH-] = 1.0 x 10-7M
Yesterday’s Homework
[OH-] = 1.0 x 10-7M[H+] = 1.0 x 10-7M
Yesterday’s Homework
[OH-] = 1.0 x 10-7M[H+] = 1.0 x 10-7M
neutral
Yesterday’s Homework
[OH-] = 1.0 x 10-3M
Yesterday’s Homework
[OH-] = 1.0 x 10-3M[H+] = 1.0 x 10-11M
Yesterday’s Homework
[OH-] = 1.0 x 10-3M[H+] = 1.0 x 10-11M
basic
Yesterday’s Homework
Any questions?
Daily Quiz Questions
Daily Quiz Questions
1. What is true of [H+] and [OH-]?
a. [H+] = [OH-]
b. [H+] x [OH-] = 1 x 10-7
c. [H+] ÷ [OH-] = 1 x 10-7
d. [H+] x [OH-] = 1 x 10-14
e. [H+] ÷ [OH-] = 1 x 10-14
Daily Quiz Questions
2. In a neutral solution, pH =
a. 0
b. 0.5
c. 1
d. 7
e. 14
Daily Quiz Questions
3. 1 x 10-5 = ?
a. 5
b. 100,000
c. 0.000,01
d. 0.000,001
Daily Quiz Questions
4. Which number is bigger?
a. 1 x 10-2
b. 1 x 10-6
.
Daily Quiz Questions
1. What is true of [H+] and [OH-]?
a. [H+] = [OH-]
b. [H+] x [OH-] = 1 x 10-7
c. [H+] ÷ [OH-] = 1 x 10-7
d. [H+] x [OH-] = 1 x 10-14
e. [H+] ÷ [OH-] = 1 x 10-14
Daily Quiz Questions
1. What is true of [H+] and [OH-]?
a. [H+] = [OH-]
b. [H+] x [OH-] = 1 x 10-7
c. [H+] ÷ [OH-] = 1 x 10-7
d. [H+] x [OH-] = 1 x 10-14
e. [H+] ÷ [OH-] = 1 x 10-14
Daily Quiz Questions
2. In a neutral solution, pH =
a. 0
b. 0.5
c. 1
d. 7
e. 14
Daily Quiz Questions
2. In a neutral solution, pH =
a. 0
b. 0.5
c. 1
d. 7
e. 14
Daily Quiz Questions
3. 1 x 10-5 = ?
a. 5
b. 100,000
c. 0.000,01
d. 0.000,001
Daily Quiz Questions
3. 1 x 10-5 = ?
a. 5
b. 100,000
c. 0.000,01
d. 0.000,001
Daily Quiz Questions
4. Which number is bigger?
a. 1 x 10-2
b. 1 x 10-6
Daily Quiz Questions
4. Which number is bigger?
a. 1 x 10-2
b. 1 x 10-6
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 or, if the number is in scientific notation, look at the exponent.
Logarithms
1 = 1 x 100
10 = 1 x 101
100 = 1 x 102
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
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.
1 x 108 = 100,000,000
Logarithms
You can multiply two numbers by adding their logarithms.
1 x 108 = 100,000,000
0 + 8 = 8
Logarithms
You can multiply two numbers by adding their logarithms.
2 x 108 = 200,000,000
? + 8 = ?
Logarithms
So what’s the logarithm of 2? You have to look it up.
2 x 108 = 200,000,000
? + 8 = ?
Logarithms
So what’s the logarithm of 2? You have to look it up.
2 x 108 = 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
You can find the logarithm of any number by pressing the “log” key on a calculator…
Logarithms
You can find the logarithm of any number by pressing the “log” key on a calculator…
but
Logarithms
You can find the logarithm of any number by pressing the “log” key on a calculator…
but
…if you don’t understand what the calculator is doing, the
information is useless to you.
Logarithms
Try a few!
Logarithms
log 103 =
Logarithms
log 103 = 3
Logarithms
log 108 =
Logarithms
log 108 = 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 1012 =
Logarithms
log 4 x 1012 = 0.602 + 12
Logarithms
log 4 x 1012 = 12.602
Logarithms
log 8.3 x 105 =
Logarithms
log 8.3 x 105 = 0.919 + 5
Logarithms
log 8.3 x 105 = 5.919
Logarithms
log 7.1 x 10-3 =
Logarithms
log 7.1 x 10-3 = 0.851 - 3
Logarithms
log 7.1 x 10-3 = -2.149
Logarithms
log 4.8 x 10-11 =
Logarithms
log 4.8 x 10-11 = 0.681 - 11
Logarithms
log 4.8 x 10-11 = -10.319
pH
pH = -log [H+]pOH = -log [OH-]
pH + pOH = 14
[H+] = 0.0035
What is the pH?
What is the pOH?
Is it acidic or basic?
[H+] = 0.0035
[H+] = 0.0035
0.0035 = 3.5 x 10-3
[H+] = 0.0035
0.0035 = 3.5 x 10-3
log 0.0035 = log 3.5 + log 10-3
[H+] = 0.0035
0.0035 = 3.5 x 10-3
log 0.0035 = log 3.5 + log 10-3
= 0.544 – 3
[H+] = 0.0035
0.0035 = 3.5 x 10-3
log 0.0035 = log 3.5 + log 10-3
= 0.544 – 3
= –2.456
[H+] = 0.0035
0.0035 = 3.5 x 10-3
log 0.0035 = log 3.5 + log 10-3
= 0.544 – 3
= –2.456
pH = 2.456
[H+] = 0.0035
pH = 2.456
pOH = 14 – 2.456
= 11.544The solution is acidic.
Homework
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