Answer:

litmus

Answer	Crossword Clue
LITMUS	Dye used by chemists
LITMUS	Acid-base test dye
LITMUS	Benchmark test

LITMUS	It turns blue in an alkali
LITMUS	It turns red in acid
LITMUS	.. test: pH indicator
LITMUS	Chem test paper?
LITMUS	Substance in acid tests
LITMUS	Chemical indicator
LITMUS	... test
LITMUS	Acid or base indicator

LITMUS	It turns blue in acid
LITMUS	Word before paper or test
LITMUS	Acid-testing paper
LITMUS	Word with test or paper
LITMUS	Acid test material
LITMUS	Acid-base indicator.
LITMUS	... paper.
LITMUS	Acid indicator

LITMUS	Kind of paper or test
LITMUS	Kind of test
LITMUS	Blue coloring matter
LITMUS	Type of test
LITMUS	Kind of test or paper
LITMUS	Acid test?

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.