Question

the principle of limit test for arsenic is based on mcq​

Answer 1

Answer:

Explanation:

Limit test of Arsenic is based on the reaction of arsenic gas with hydrogen ion to form yellow stain on mercuric chloride paper in presence of reducing agents like potassium iodide. 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, etc. Arsenious acid is further reduced to arsine (gas) by hydrogen and reacts with mercuric chloride paper to give a yellow stain.

Answer 2

Answer:

Limit test of Arsenic is based on the reaction of arsenic gas with hydrogen ion which form yellow stain on mercuric chloride paper in presence potassium iodide. It requires special apparatus.

Explanation:

• Arsenic that is present as arsenic acid in the sample will be reduced to arsenious acid in the presence of potassium iodide.

• Arsenious acid will converted to arsine by hydrogen that reacts with mercuric chloride paper and will give a yellow stain.