PH Indicators - Lab Report Example

Download file to see previous pages... Maintaining the pH is critical in any industrial processes employing enzymes. A few examples would be papain from the leaves and unripe fruit of the pawpaw (Carica papaya) has been used to tenderise meats. Amylase is used in starch hydrolysis. Now gluco-amylase functions at pH 4.5 whereas fungal amylase at pH 5.5. Lactose hydrolysis is carried out by lactase for Aspergillus niger and A.oryzae at pH optima (pH 4.5-6.0 and 3.0-4.0, respectively)
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6.698970004

Useful range for the indicator: 8.69- 10.69

Indicator: Alizarin Yellow

Test Tube
Color After Adding the Indicator
[OH-]
pOH
pH
1
red
0.05

12.69897
2
orange
0.005

11.69897
3
yellow
0.0005

10.69897
4
yellow
0.00005

9.698970004
5
yellow
0.000005

8.698970004
6
yellow
0.0000005

7.698970004
7
yellow
0.00000005

6.698970004

Useful range for the indicator: 10.69-12.69

Indicator: Red Cabbage extract

Test Tube
Color After Adding the Indicator
[OH-]
pOH
pH
1
green-blue
0.05

12.69897
2
aqua blue
0.005

11.69897
3
aqua blue
0.0005

10.69897
4
sky blue
0.00005

9.698970004
5
Dark blue
0.000005

8.698970004
6
Violet
0.0000005

7.698970004
7
Pink
0.00000005

6.698970004

Useful range for the indicator: 6.69-8.89





Which indicator is the best to use for observing pH changes:

near pH = 7 : Bromothymol Blue, Red Cabbage Extract

near pH = 8 : Red Cabbage Extract

near pH = 10 : Phenolphthalein

near pH = 12 : Alizarin Yellow



1. Locate an industry, occupation, industrial process, etc., where pH is critical to success.
Ans: Enzymes are biocatalysts which carry out biochemical reactions at rigid conditions of temperature and pH. Enzymes are used in multiple areas in Pharmaceutical, biotech and food industries where it is critical to maintain the pH of the process for optimal functioning of the enzymes. Maintaining the pH is critical in any industrial processes employing enzymes. A few examples would be papain from the leaves and unripe fruit of the pawpaw (Carica papaya) has been used to tenderise meats. Amylase is used in starch hydrolysis. Now gluco-amylase functions at pH 4.5 whereas fungal amylase at pH 5.5. Lactose hydrolysis is carried out by lactase for Aspergillus niger and A.oryzae at pH optima (pH 4.5-6.0 and 3.0-4.0, respectively)

2. Is ...Download file to see next pagesRead More