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When using the phenol red carbohydrate broth fermentation test at what pH is the pH indicator yellow?
below 6.8
What color is phenol red at neutral pH?
it becomes an orange-red color
Which is more polar phenol or ethanol?
Yes , phenol is more polar than toluene. because ph-OH has more dipole moment than Ph-CH3
What is the pka of bromophenol blue?
Phenols are acidic substances (pH over 7).
How are acids and bases measured by a pH indicator?
Testing the Acidity of Pools Because most pools are kept in a pH range of 7.2-7.6, the pH test that uses phenol red as a reagent is particularly effective. Add the specified number of drops of liquid, to the water sample, and compare the resulting colour to the test-kit standard.
Suggest a chemical test(s) to distinguish ethanol and phenol. Include the reagents reaction conditions and observations. And the equation?
Phenol solution, or phenol directly from the manufacturer?If the phenol is in the form it comes in from the factory, no chemical test is necessary. Phenol is a white crystalline solid.If it's dissolved in water, the easiest test is pH. Phenol solution is more acidic than ethanol. So...whatever you use for a pH test will do ya.
What reaction do you get when you mix phenol red with acids and bases?
Phenol red is yellow under pH=6,8 and pink over a pH=8,2.
Purpose of the phenol red in the medium?
Phenol red acts as the pH indicator. Turning yellow as the ph lowers (acidic environments) and deep red when the ph is high (alkaline environment)
Does phenol red change baking soda to red?
Phenol red is a pH indicator. The baking soda is not changing color, but the phenol red is.
What color is phenol red at an base pH?
green
What color is phenol red at an acid pH?
yellow
Explain the purpose of the phenol red in the medium?
To determine if a bacterium can ferment a particular carbohydrate and determine the end products of that fermentation
What is the pH indicator in TSI agar?
Phenol Red
What is the PH level on well water?
It always varies, but ideally is about 6.8 - 7.00
When using the phenol red carbohydrate broth fermentation test at what pH is the pH indicator yellow?
below 6.8
What does red indicate?
Phenol red indicates for acidic pH. When the red solution turns yellow it means the solution has a low pH. For Example: CO2 dissolves into water and forms carbonic acid which lowers the pH and the solution would turn yellow.
HOW IS IT POSSIBLE FOR AN ORGANISM TO BE POSITIVE FOR GLUCOSE USE IN A PHENOL RED TEST BUT NEGATIVE IN THE METHYL RED TEST?
Methyl red differs from Phenolred (which is used in the fermentation test and the MSA plates) in that it is yellow at pH 6.2 and above and red at pH 4.4 and below. Phenol red turns yellow below a pH of 6.8. If you get a positive with methyl red and a negative with phenol red, the pH has to be between 6.7 and 6.1.
