7.2.5 pH
Normal range of urinary pH is 4.5–7.5. Various factors like heavy meals, heavy
exercise, metabolic acidosis, or chronic respiratory acidosis influence urine pH
greatly. Normally freshly voided urine is acidic.
7.3 Chemical Examination of Urine
Normal urine has various organic and inorganic constituents. The normal inorganic
constituents are chloride, phosphates, sulphates, calcium, etc., while organic
constituents are urea, uric acid, and creatinine.
7.4 Tests for Inorganic Constituents of Urine
Chloride Add few drops of 3% silver nitrate solution to about 3 ml of urine sample.
White precipitates appear due to the presence of chloride, carbonate, or phosphates.
Addition of 3–5 drops of conc. HNO 3 leaves white precipitate of silver chloride only
and dissolves carbonates and phosphates.
Fig. 7.1Urinometer
7.4 Tests for Inorganic Constituents of Urine 31