什么是石蕊

Litmus is a water-soluble mixture of different dyes extracted from lichens, especially Roccella tinctoria.石蕊是从地衣，尤其是Roccella tinctoria中提取的不同染料的水溶性混合物。 The mixture has CAS number 1393-92-6.该混合物的CAS号为4.5-8.3-25。 It is often absorbed onto filter paper.它通常被吸收到滤纸上。 The resulting piece of paper or solution with water becomes a pH indicator (one of the oldest), used to test materials for acidity.所得的纸或用水溶解的溶液成为pH指示剂（最古老的一种），用于测试材料的酸度。 Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic (ie alkaline) conditions,the color change occurring over the pH range 10-15 (at XNUMX°C).蓝色石蕊试纸在酸性条件下会变成红色，而红色石蕊试纸在碱性（即碱性）条件下会变成蓝色，颜色变化发生在pH范围XNUMX-XNUMX（在XNUMX°C）下。 Neutral litmus paper is purple in colour.The mixture contains XNUMX to XNUMX different dyes (erythrolitmin (or erythrolein), azolitmin, spaniolitmin, leucoorcein and leucazolitmin).中性石蕊试纸为紫色，混合物中包含XNUMX至XNUMX种不同的染料（赤藓素（或赤藓精），偶氮立胺，司潘立利敏，白细胞素和白细胞唑胺）。 Pure azolitmin does show nearly the same effect as litmus.纯偶氮立敏确实显示出与石蕊几乎相同的效果。