Precipitated iron was dissolved in hydrochloric acid, pH=2 was adjusted with ammonia, and sulfosalicylic acid was used as an indicator to determine iron by EDTA.
(2) Reagent ammonia; hydrochloric acid; 10% sulfosalicylic acid solution; 0.05mol/L EDTA standard solution.
(3) Analysis steps
1 Take the iron precipitated in Step 2 of the analysis nickel and dissolve the precipitate with a small amount of hydrochloric acid on the filter paper to obtain an iron-containing solution. The filter paper is washed with hot water several times. The filtrate and washings are combined in a 250-mL volumetric flask, and the water is added to the mark.
2 Take the test solution 25mL, add water 50mL, add ammonia to pH = 2, (using 0.5 to 5 precision test paper).
3 heated to 50 ~ 60 °C, plus sulfosalicylic acid 1mL; red.
4 Titrate with 0.05 mol/L EDTA standard solution until the end of light yellow, using EDTA solution V (mL).
(4) Calculation
