释义 |
methyl orange noun Usage: sometimes capitalized M&O : a basic azo dye (CH3)2NC6H4N . NC6H4SO3Na which is made by coupling diazotized sulfanilic acid with dimethylaniline, is used chiefly as an acid-base indicator, and whose dilute solution is yellow when neutral and pink when acid — see dye table I (under Acid Orange 52); compare helianthin |