1. Load a burette with 0,1 N sodium hydroxide solution.
2. To conical flask pour in 10 ml aliquot of sample (VS).
3. Add 10 ml of 0,1 N sulphuric acid solution (VH2SO4).
4. Introduce 2-3 drops of methyl orange solution, and titrate with 0,1 N sodium hydroxide solution
until the solution just begin to change colour from red to yellow. Read the burette mark (Vmo).
5. Repeat titration also two times. Calculate the median volumes of used sodium hydroxide
solution.
6. Calculate ammonia percentage in sample:
xNH3 =
(V N V N ) meq
V
H SO H SO mo NaOH NH
S
2 4 2 4 3
× − × ×
×100%
M.m. NH3 = 17,0304