litmus
pH testing dye
Litmus is a dye derived from lichen that turns red in acid and blue in base, used to test acidity.
The figurative litmus test has become far more common than the laboratory one—any single criterion that decisively reveals someone's position or character: Abortion has become a litmus test for Supreme Court nominees.
Measure of solution acidity
- acidLow-pH chemical compound
- baseSupporting bottom structure
- alkalineHaving high pH
- acidicBelow neutral pH
neutral · titration · buffer · solution · pH scale · pH meter · test · measurement
Standard for judgment
- benchmarkStandard for comparison
- standardLevel of quality accepted
- decisiveQuick to conclude
- judgmentReasoned decision-making capacity
measure · threshold · pass-fail · determining · definitive · proof · trial · verification
Primary color, warm
- bluePrimary color; also sad
- purpleHue between crimson and azure
- transitionChange from one state
- dyePigment for changing hues
pigment · hue · spectrum · tint · shade · gradation · color shift · visual
Act of removing
- naturalNot artificially produced
- organicFrom living matter
- plant-derivedOriginating from flora
- medievalOf the Middle Ages
traditional · purple dye · textile · fermentation · ammonia
pH
Measure of solution acidity
acidic · neutral · titration · buffer · solution · pH scale · pH meter · test · measurement · concentration
criterion
Standard for judgment
judgment · measure · threshold · pass-fail · determining · definitive · proof · trial · verification · gauge
red
Primary color, warm
- bluePrimary color; also sad
- purpleHue between crimson and azure
- transitionChange from one state
dye · pigment · hue · spectrum · tint · shade · gradation · color shift · visual · reaction
extraction
Act of removing
- naturalNot artificially produced
- organicFrom living matter
- plant-derivedOriginating from flora
medieval · traditional · purple dye · textile · fermentation · ammonia
- pH indicatorsphenolphthalein, bromothymol blue, pH paper, pH strips, alizarin
- colorantsdye, dyes, pigment, pigments, tint
- Lab Chemicalssodium hydroxide, acetic acid, hydrogen peroxide, potassium chloride, sodium chloride
- pHacidic, alkaline, neutral, acidity, acid
- lab reagentsreagent, buffer, buffers, formalin, pyridine
- pH ChemistrypH, acid, acids, base, bases
litmusthermometer
Heat-measuring instrument
barometer · hygrometer · voltmeter · scale · spectrometer
litmusambiguity
Openness to multiple interpretations
gray area · indeterminate · inconclusive · equivocal · spectrum
- litmus testSingle determining factor
- litmus paperAcid-base detection tool