EXAMPLE OF TITRATION

1) paracetamol:

Physico-chemical data:
CAS number: 103-90-2
C₈H₉NO₂
Molecular weight: 151.2 g.mol^-1
White crystalline powder
Quite soluble in water, easily soluble in alcohol, very slightly soluble in dichloromethane.
Mp: 168-172°C
pKa: 9.5 (25°C)

Maximum absorption: λmax at acidic pH: 245 nm (E^1%(1cm) = 668), λmax at basic pH: 257 nm (E^1%(1cm) = 715).

2) sulfamethoxazole

CAS number: 723-46-6
C₁₀H₁₁N₃O₃S
Molecular weight: 253.3 g.mol^-1
White or yellowish crystalline powder
Very slightly soluble in water, easily soluble in alcohol.
Mp: 168-172°C
pKa: 5.6 (25°C)

Maximum absorption: λmax at acidic pH: 265 nm (E^1%(1cm) = 175), λmax at basic pH: 256 nm (E^1%(1cm) = 673).