ph指示剂（PH indicator）.docVIP

ph指示剂（PH indicator） PH indicator Common indicators 1 ethoxy yellow Chijing indicator extraction ethoxy Chijing yellow 0.1g, add 100ml of ethanol to dissolve, i.e.. Color change range pH3.5 ~ 5.5 (red to yellow). Two methyl yellow indicator solution, take two methyl yellow 0.1g. Add ethanol to 100ml to make dissolved. Color change range pH2.9 ~ 4 (red to yellow). 2 two methyl yellow methylene blue mixed indicator solution two methyl yellow methylene blue and the 15mg, add chloroform 100ml, shake to dissolve (when necessary, filtration, is lukewarm). 3, two methyl yellow - solvent Blue 19 mixed indicator solution, take two methyl yellow and solvent Blue 19 15mg, chlorination 100ml, so that dissolved, that is. 4, two, cresol, orange, indicating liquid, take two cresol orange 0.2g, add water 100ml to dissolve, that is. 5, two benzene hydrazine hydrazine liquid, take two benzene hydrazine 1g, and ethanol 100ml dissolved, that is. 6 catechol violet indicator liquid take catechol violet 0.1g, add water 100ml to dissolve, namely get. The range of color change is pH6.0 ~ 7 to 9 (yellow, purple, purplish red). 7 neutral red indicator, take the neutral red 0.5g, add water to dissolve into 100ml, filter, that is. Color change range pH6.8 ~ 8 (red to yellow). 8 0.3g extraction of malachite green malachite green indicator, 100ml of glacial acetic acid to dissolve, i.e.. Discoloration range pH0.0 to 2 (yellow to green); 11 to 13.5 (green to colorless) 9 extraction of litmus litmus instructions powder 10g, add 40ml of ethanol, reflux boiling 1 hours, static, decanted supernatant, use the same method to deal with 2 times, each time 30ml ethanol, the residue of water washing 10ml, pour lotion, then add 50ml of water boil, cooling, filtration, i.e.. Color change range pH4.5 ~ 8 (red to blue). 10 methyl red indicator solution, take methyl red 0.1g, plus 0.05mol/L sodium hydroxide solution 7.4ml, dissolve, and then dilute with water to 200ml, that is. Color change range pH4.2 ~ 6.3 (red