6.what is the usage of ethanol in limit test for sulphate?
7.what is the usage of granulated Zn/hcl in the limit test for arsenic?
8. Why the Cotton wool is dipped into lead acetate and used into the limit test for arsenic?
9.What is the uses of KI /HCl in limit test for arsenic?
Answers
Explanation:
6.what is the usage of ethanol in limit test for sulphate?
7.what is the usage of granulated Zn/hcl in the limit test for arsenic?
8. Why the Cotton wool is dipped into lead acetate and used into the limit test for arsenic?
9.What is the uses of KI /HCl in limit test for arsenic?
6) The limit test for sulphate is based on the reaction between barium chloride and soluble sulphates in presence of dilute hydrochloric acid. Then the turbidity produced is compared with the standard turbidity
7) It is also called as Gutzeit test and requires special apparatus. Arsenic, present as arsenic acid in the sample is reduced to arsenious acid by reducing agents like potassium iodide, stannous acid, zinc, hydrochloric acid
8) Cotton wool dipped in lead acetate solution is used to trap any hydrogen sulphide gas liberated with arsine gas.
9) Stannous chloride is used for complete evolution of arsine. Zinc, potassium iodide and stannous chloride is used as a reducing agent. Hydrochloride acid is used to make the solution acidic. hydrogen sulphide, which may be evolved along with arsine.