Factory Supply Bromocresol Green Cas 62625 - 32 - 5 With Best Price: User Guide

Basic Information and Parameters

Bromocresol Green, with the CAS number 62625 - 32 - 5, is a commonly used pH indicator. It is a dye that changes color depending on the pH level of the solution it is in. The chemical formula of Bromocresol Green is C₂₁H₁₄Br₄O₅S. It appears as a light - green to yellowish - green crystalline powder.

The solubility of Bromocresol Green is relatively low in water but it can dissolve well in ethanol, methanol, and other organic solvents. The pH range at which it changes color is approximately between 3.8 and 5.4. In acidic solutions (pH < 3.8), it is yellow, and in basic solutions (pH > 5.4), it is blue - green.

Uses of the Product

One of the primary uses of Bromocresol Green is as a pH indicator in laboratories. It is widely used in titration experiments, especially those involving weak acids and bases. For example, in acid - base titrations to determine the concentration of an unknown acid or base, Bromocresol Green can help to accurately identify the endpoint of the reaction by the color change.

In the field of microbiology, Bromocresol Green can be used in culture media. It can help to monitor the growth of bacteria and fungi. As microorganisms grow and metabolize, they can change the pH of the culture medium, and the color change of Bromocresol Green can provide a visual indication of these changes.

It also has applications in the food industry. Bromocresol Green can be used to test the freshness of certain food products. For instance, it can detect changes in the pH of dairy products, which can be an indicator of spoilage.

How to Use the Product

When using Bromocresol Green as a pH indicator in titration:

1. First, prepare a suitable solution of Bromocresol Green. Usually, it is dissolved in ethanol or other appropriate solvents at a certain concentration. For example, a 0.1% solution can be prepared by dissolving 0.1 g of Bromocresol Green in 100 mL of ethanol.
2. Add a few drops of the prepared Bromocresol Green solution to the sample solution. The exact number of drops may depend on the volume of the sample, but generally, 2 - 3 drops are sufficient for a 25 - 50 mL sample.
3. Then, start the titration process. Slowly add the titrant to the sample solution while continuously swirling the flask. Observe the color change of the solution. When the color changes from yellow to blue - green (or vice - versa depending on the type of titration), it indicates that the endpoint of the titration has been reached.

When using it in microbiology culture media:

1. Add the appropriate amount of Bromocresol Green to the culture medium during the preparation process. The concentration should be carefully controlled according to the specific requirements of the experiment.
2. After inoculating the microorganisms into the culture medium, incubate the culture at the appropriate temperature. Monitor the color change of the culture medium over time to assess the growth and metabolic activities of the microorganisms.

Detailed Use Cases

Case 1: Acid - Base Titration in a Chemistry Laboratory
A chemistry student is tasked with determining the concentration of acetic acid in a vinegar sample. First, a 0.1% Bromocresol Green solution is prepared. A 25 mL sample of vinegar is taken and a few drops of the Bromocresol Green solution are added. The solution turns yellow, indicating an acidic environment. Then, a standardized sodium hydroxide solution is slowly added to the vinegar sample. As the titration progresses, the color of the solution gradually changes from yellow to a greenish - hue. At the endpoint, the solution turns blue - green. By recording the volume of sodium hydroxide solution used, the student can calculate the concentration of acetic acid in the vinegar sample.

Case 2: Monitoring Bacterial Growth in a Microbiology Lab
A researcher is studying the growth of a particular strain of bacteria in a culture medium. Bromocresol Green is added to the culture medium at a concentration of 0.01%. After inoculating the bacteria, the culture is incubated at 37°C. Initially, the culture medium is yellow. As the bacteria