Question

Fluoride ion concentration in polluted water is detected by:

A) Conc. $HCl$ and $H_{2}S$ gas.

B) Zirconium Alizarin-S dye.

C) Sodium nitroprusside.

• A. $A$ and $B$
• B. $B$
• C. $C$
• D. $A$ and $C$

Answer 1

The correct option is B $B$

Fluoride detection is polluted water can be done by the Zirconium-Alizarin method. A sensitive colour range is obtained for amounts a range from 0.0 to 1.6 ppm when 100ml sample is used for Zirconium-Alizarin method. Zirconium-Alizarin method is a convenient rapid colorimetric method using the Zirconium- Alizarin indicator with $H_{2}S{O}_4$ for the determination of fluoride in water.