Methyl Red is water soluble. Why??

Question

SO I have the qurstion: Which functional groups make methyl red water soluble?

so im thinking the CO2H but don't know about the diazenyl or the dimethylamino group because they both have nitrogen present so do the form a hydrogen bond with the hydrogen on H2O

Answer 1

Not sure where you got the idea that methyl red is soluble in water. At neutral pH, it would be very marginally soluble in water, if at all. The CO₂H group will make it more soluble once it is ionized or by protonating the dimethylamino group. Otherwise, it isn't soluble in water.