What are the indicated discoloration ranges of methyl red and methyl orange respectively?

The pH value of methyl red ranges from 4.4 (red) to 6.2 (yellow), and the pH value of methyl orange is red below 3. 1, yellow above 4.4, and orange between 3. 1 ~ 4.4.

On October 27th, 2065438+071KLOC-0, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference, and methyl red was among the three types of carcinogens.

Methyl orange, whose structural name is sodium p-dimethylaminoazobenzene sulfonate, is used for pH control of chemical reactions and acid-base titration analysis of chemical products and intermediates in laboratories and industrial and agricultural production.

Extended data:

Storage methods of methyl red and methyl orange;

1, stored in a cool, dry and well-ventilated warehouse. Stay away from fire and heat sources. Avoid direct sunlight.

2. The package is sealed. Should be stored separately from acids and edible chemicals, and should not be mixed.

3. The storage area should be equipped with suitable materials to control leakage.

References:

Baidu encyclopedia-methyl orange

References:

Baidu encyclopedia-methyl red