Litmus a water-soluble dye is extracted from lichens. This standard pH indicator changes color in response to acidic or basic medium. In acidic environments, it turns red, while in basic environments, it turns blue. The word “litmus” derives from an Old Norse word for “moss used for dyeing.” Litmus is derived from lichens like Roccella tinctoria, Roccella fuciformis, and so forth. The dye mixture comprises diverse components, primarily a 7-hydroxyphenoxazone chromophore, responsible for its color-changing properties.
Litmus preparation, lichens are treated with sodium carbonate and ammonia, resulting in a blue dye after several weeks. The dye is then purified and used in litmus paper, which remains a classic method for detecting pH changes.
CAS No.: 1393-92-6
Synonyms: litmus test; crucible; cross; acid test; ordeal; gauntlet; fire; gantlet
| Physical Properties | |
| Chemical formula | C9H10O5N (Blue litmus paper) C13H22O6 (Red litmus paper) |
| IUPAC Name | 2-bromo-4-[3-(3-bromo-4-hydroxy-2-methyl-5-propan-2-ylphenyl)-1,1-dioxo-2,1λ6-benzoxathiol-3-yl]-3-methyl-6-propan-2-ylphenol |
| Molecular weight | 3300 g/mol |
| Solubility | Water |
| Density | 1.2 g/cm³ |
| Chemical Properties | |
| Colour | Red or Blue (determined by pH) |
| State | Powder or granules |
| Melting point | 100°C |
| λmax | 580 nm |
| pH | 4.5 – 8.3 |
| Pictograms : | |
| Hazard Statements : | This chemical is considered nonhazardous according to GHS classifications for the Hazard Communication Standard. Treat all laboratory chemicals with caution. |
| Precautionary statements : | Although this material is considered to be nonhazardous, unpredictable reactions among chemicals are always possible. Prudent laboratory practices should be observed. |
Litmus a water-soluble dye is extracted from lichens. This standard pH indicator changes color in response to acidic or basic medium. In acidic environments, it turns red, while in basic environments, it turns blue. The word “litmus” derives from an Old Norse word for “moss used for dyeing.” Litmus is derived from lichens like Roccella tinctoria, Roccella fuciformis, and so forth. The dye mixture comprises diverse components, primarily a 7-hydroxyphenoxazone chromophore, responsible for its color-changing properties.
Litmus preparation, lichens are treated with sodium carbonate and ammonia, resulting in a blue dye after several weeks. The dye is then purified and used in litmus paper, which remains a classic method for detecting pH changes.
CAS No.: 1393-92-6
Synonyms: litmus test; crucible; cross; acid test; ordeal; gauntlet; fire; gantlet
| Physical Properties | |
| Chemical formula | C9H10O5N (Blue litmus paper) C13H22O6 (Red litmus paper) |
| IUPAC Name | 2-bromo-4-[3-(3-bromo-4-hydroxy-2-methyl-5-propan-2-ylphenyl)-1,1-dioxo-2,1λ6-benzoxathiol-3-yl]-3-methyl-6-propan-2-ylphenol |
| Molecular weight | 3300 g/mol |
| Solubility | Water |
| Density | 1.2 g/cm³ |
| Chemical Properties | |
| Colour | Red or Blue (determined by pH) |
| State | Powder or granules |
| Melting point | 100°C |
| λmax | 580 nm |
| pH | 4.5 – 8.3 |
| Pictograms : | |
| Hazard Statements : | This chemical is considered nonhazardous according to GHS classifications for the Hazard Communication Standard. Treat all laboratory chemicals with caution. |
| Precautionary statements : | Although this material is considered to be nonhazardous, unpredictable reactions among chemicals are always possible. Prudent laboratory practices should be observed. |
Red litmus paper will turn blue in a basic or alkaline cleaning spray.
Red litmus paper would turn blue in dishwashing detergent, as it is typically a basic solution.
In a neutral solution, litmus paper generally remains purple.
