Titration and Indicators Flashcards
What are the types of Litmus Paper
Synthetic and Natural
paper that has been dipped in a substance that will undergo a color change when it is dipped in either an acid or base
Litmus paper
is called an indicator because it is used to indicate whether the solution is an acid or base
Litmus paper
If the red litmus paper turns blue
solution is basic (ph>7)
if the blue litmus paper turns red
solution is acidic (ph<7)
substance that changes color at a specific pH and is used to indicate the pH of the solution
indicator
active ingredient in indicator
anthrocyanin
is a common garden plant with flowers that may come in many colors depending on the pH of the soil
hydrangea
blue hydrangea flowers means
soil is acidic
creamy white hydrangea flowers means
soil is neutral
pink hydrangeo flowers means
soil is basic
indicator that is produced from a substance that is naturally occurring or is itself a naturally occurring substance
natural indicator
examples of natural indicator
red beets
blueberries
cranberries
What is the active ingredient found in natural indicator?
anthrocyanin
compounds created in a chemistry lab rather than compounds found in nature
synthetic indicators
True or False: both naturally occurring indicators and synthetic indicators are weak organic acids or bases
true
What is a common synthetic indicator used in most chemistry laboratories
Phenolphthalein
indicator that changes color at pH of 8.2 whereas it is colorless before 8.2 and after it is pink
phenolphthalein
What is the color of Phenolphthalein before pH is 8.2?
colorless
What is the color of Phenolphthalein after pH is 8.2
pink
changes color from ph 3.2 to 4.4
methyl orange
color of methyl orange below 3.2
red
above 4.4 color of methyl orange
yellow
between 3.2 and 4.4 of methyl orange
orange
donates a proton
Bronsted-Lowry acid
accepts a proton
Bronsted-Lowry base
What are the requirements for a substance to function as an acid-base indicator?
substance must have an equilibrium affected by hydrogen ion concentration
two forms of compound on different sides of equilibrium must have different color
pH range of methyl violet
0.0 - 1.6
ph range of thymol blue
1.2 - 2.8
orange IV ph range
1.3 - 3.0
methyl orange ph range
3.2 - 4.4
bromphenol blue pH range
3.0 - 4.7
congo red pH range
3.0 - 5.0
bromocresol green pH range
3.8 - 5.4
methyl red pH range
4.8 - 6.0
litmus pH range
5.0 - 8.0
chlorophenol red pH range
4.8 -6.2
bromothymol blue pH range
6.0 - 7.6
phenol red pH range
6.4 - 8.2
thymol blue pH range
8.0 -9.6
phenolphthalein pH range
8.2 - 10.0
thymolphthalein pH range
9.4 - 10.6
alizarin yellow R ph range
10.1 - 12.0
Methyl blue pH range
10.6 - 13.4
indigo carmine pH range
11.4 - 13.0
color range of methyl violet
yellow-blue
color range of thymol blue
red-yellow
color range of orange IV
red-yellow
color range of methyl orange
red-orange
color range of bromphenol blue
orange/yellow-violet
color range of congo redd
blue-red
color range of bromocresol green
yellow-blue
color range of methyl red
red-yellow
color range of litmus
red-blue
color range of chlorophenol red
yellow-red
color range of bromothymol blue
yellow-blue
color range of phenol red
yellow-red/violet
color range of thymol blue
yellow-blue
color range of phenolphthalein
colorless-pink
color range of thymolphthalein
colorless-blue
color range of alizarin yellow R
yellow-red
color range of methyl blue
blue-pale violet
color range of indigo carmine
blue-yellow
solution that has a different color for each pH from 0-14
universal indicator
produced by creadively mixing many of the individual indicators together so that a different color is achieved for each different pH
universal indicator
substance that changes color at a specific pH and is used to indicate the pH of the solution
indicator
produced from a substance that is naturally occurring or is itself a naturally occurring substance
natural indicator
normally an organic weak acid or base with usually complicated structure
synthetic indicator
solution that has a different color for each pH from 0-14
Universal indicator
