Complete Step-by-Step Guide to Preparing Phenol Red Indicator for Laboratory Applications скачать в хорошем качестве

Complete Step-by-Step Guide to Preparing Phenol Red Indicator for Laboratory Applications

Phenol Red (Phenolsulfonphthalein): 4,4'-(3H-2,1-benzoxathiol-3-ylidene) diphenol S,S-dioxide, C₁₉H₁₄O₅S = 354.4 Phenol Red Very slightly soluble in water, slightly soluble in ethanol, readily soluble in alkaline solutions. Preparation: Dissolve 0.1 g of phenol red in a mixture of 2.82 ml of 0.1 N sodium hydroxide solution and 20 ml of 96% ethanol , then add water to make up to 100 ml. Sensitivity: Take 100 ml of carbon dioxide–free water , add 0.1 ml of phenol red solution; the solution is yellow. Upon adding not more than 0.1 ml of 0.02 N sodium hydroxide solution, the color must change to red-violet. Don’t forget to hit Like and Subscribe to see more chemistry experiments from VNChemLab! Contact email: vnchemlab@gmail.com #VNChemLab #ChemistryEducation #ChemistryExperiments #thinghiemhoahoc