51812 Go over pg 7475 and concept review Lecture Indicators and pH A pg 7677 Universal Indicator Bases Acids Phenolpthalein Indicator Identifies if a base is present turns pink ID: 729908
Download Presentation The PPT/PDF document "Goals to Accomplish Today" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Goals to Accomplish Today 5.18.12
Go over pg. 74-75 and concept review
Lecture: Indicators and pH
(A) pg. 76-77Slide2
Universal Indicator
Bases
AcidsSlide3
Phenolpthalein Indicator
Identifies if a base is present: turns
pinkSlide4
Litmus Paper- tells you if you have an acid or a baseSlide5
What is the pH scale and what am I really measuring?
A value to express the acidity of a solution
(power of hydrogen)
Ranges from 0-14
0-6 Acidic 7 Neutral
8-14 Basic
Measures the
hydronium
ions in a solution
The more
hydronium
ion the more acidic Slide6
pH paperSlide7
pH scale
: measures acidity/basicitySlide8
pH scale
0 1 2 3
4 5 6 7
8 9 10 11 12 13 14
ACID
BASE
NEUTRAL
Each step on pH scale represents a factor of 10.
pH 5 vs. pH 6
(10X more acidic)
pH 3 vs. pH 5 (100X different)
pH 8 vs. pH 13 (100,000X different)
: measures acidity/basicity
10x
10x
10x
Soren Sorensen
(1868 - 1939)Slide9
pH scale`Slide10
pH of Common Substances
Timberlake,
Chemistry
7
th
Edition, page 335
1.0
M
HCl
0
gastric
juice
1.6
vinegar
2.8
carbonated
beverage
3.0
orange
3.5
apple juice
3.8
tomato
4.2
lemon
juice
2.2
coffee
5.0
bread
5.5
soil
5.5
potato
5.8
urine
6.0
milk
6.4
water (pure)
7.0
drinking water
7.2
blood
7.4
detergents
8.0 - 9.0
bile
8.0
seawater
8.5
milk of
magnesia
10.5
ammonia
11.0
bleach
12.0
1.0
M
NaOH
(lye)
14.0
8
9
10
11
12
14
13
3
4
5
6
2
1
7
0
acidic
neutral
basic
[H
+
] = [OH
-
]Slide11
Calculating the pH
Since pH is dependent on the concentration of
hydronium
ions the formula for calculating pH is the following:
pH = -log[H3O+]
Example: Calculate pH if [H
3
O
+
] = 5.00 x 10
-3
M Slide12
Calculating Concentration of the Acids or Base from pH
[H3O
+
] = 10
–pHEXAMPLE: pickle juice has a pH of 3.2 What is the hydronium ion concentration?
[H3O
+
] = 10
–3.2
[H3O
+
] = 6.3 x 10
-4
M