Molecular Formula | n.a. |
Melting Point | 100 °C |
Water Solubility | Soluble in water |
Appearance | Blue powder |
Specific Gravity | 0.984 |
Color | Dark blue to bluish-black |
Odor | Odorless |
Merck | 14,5547 |
Storage Condition | RT, dark |
Stability | Stable. Incompatible with strong oxidizing agents. |
MDL | MFCD00131528 |
Physical and Chemical Properties | Lidmus indicator is an organic acid extracted from Lichens and has a complex composition. Its acid type is red and the basic type is blue, so in acidic solution, it mainly exists in the form of red acid molecules; in alkaline solution, it mainly exists in the form of blue basic ions. At room temperature, its color change range is pH5.0 (red) to 8.0 (blue). The preparation method of the test solution is to dissolve 1g litmus in 50mL of water, stand for one day and night and then filter. Add 30 mL of 95% ethanol to the filtrate and add water to dilute to 100 mL. |
Use | Preparation of litmus paper and indicator for culture medium |
Risk Codes | R40 - Limited evidence of a carcinogenic effect R36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S24/25 - Avoid contact with skin and eyes. S36/37 - Wear suitable protective clothing and gloves. S36 - Wear suitable protective clothing. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
WGK Germany | 3 |
HS Code | 32030010 |
properties | blue powder, block or cubic crystal. |
Use | is used as an example of acid-base finger, and may also be used for coloring beverages. Product physical and chemical indicators, microbial indicators are in line with the export of Japan, the United States, the European Union and other national standards. indicator for preparation of litmus paper and medium |
physical and chemical properties | litmus indicator is a kind of organic acid, which is extracted from the lichens and has complex composition. The acid form is red and the basic form is blue, so in acidic solution, it mainly exists in the form of red acid molecules; In alkaline solution, it mainly exists in the form of blue basic ions. At room temperature, its color change range is pH5.0 (red) to 8.0 (blue). The test solution was prepared by dissolving 1g of litmus in 50ml of water, allowing it to stand for one day and night and then filtering. 30 mL of 95% ethanol was added to the filtrate and diluted to 100 mL with water. |
History of discovery | litmus as a chemical indicator for testing the acidity of solutions was identified by Robert Boyle, a British chemist and chemist, 1627 -1691) first discovered and began to promote the use. How to easily measure the acidity and alkalinity of the solution, has made the Boyi ear and other scientists a big nerve, no way out. But one day, the problem in front of the Boyi ear turned around. On this day, Boyle put a newly picked bundle of beautiful violets in the laboratory of the laboratory, began to experiment. But he accidentally dropped a few drops of hydrochloric acid on the flowers of the violet. Love the flower of the Boyi ear quickly with water to rinse, at this time, Boyi ear saw the violet flowers turned into red flowers! Why does a violet turn red? Boyle felt new and excited. He was determined to find out. The experiment was carried out with HNO3, H2SO4 and CH3COOH, and the results were identical-the petals all turned red. After repeated experiments, the extract of the violet flower was identified by the POYi, which can be used to test whether the solution is acidic. The first battle was completed, but Boyle was not satisfied. He tried to find out the substance used to test the alkali. He will be able to find the flowers, herbs, bark, tubers, root, moss, lichen made of leaching solution, one by one to test them in alkaline solution in the color reaction. It was finally found that the alkaline solution made the purple liquid extracted from litmus lichen blue. Even so, Boyi still did not stop there, he thought: can we use a reagent to measure both acidity and alkalinity? He tried to drip the litmus leaching solution into the hydrochloric acid solution, and the result was the same phenomenon as the violet test for acidity-the litmus leaching solution also turned red! The problem was completely solved. Litmus reagent in case of alkali turn blue, when the acid turns red, this is the two-way indicator that boryella is looking! Since then, litmus reagent is widely used to test the acid and alkaline solution. The major invention of Boyi was made in 1646 and is still widely used today. So, today we can very easily detect the acidity of the solution, which should be thanks to the great Boyle! |