Sample waste water in a beaker 10 ml clear example of the Erlenmeyer flask 250 ml refill solution of potassium dichromate in 1 N, 10 ml of sulfuric acid Rick 20 ml put on trial and Blank set aside. 1 night
Weigh sample fertilizer water in a beaker Size 10 ml clear examples into the Erlenmeyer flask 250 ml เติมสาร dissolved potassium dichromate 1 N. The 10 ml and sulfuric acid 20 ml, put in the sample and Blank set left 1 night.