Identify the correct statements from the following: i. In the presence of UV light, \(\mathrm{CF}_2…
Identify the correct statements from the following:
i. In the presence of UV light, \(\mathrm{CF}_2 \mathrm{Cl}_2(g)\) gives chlorine free radicals which will react with \(\mathrm{O}_3(g)\) to form \(\mathrm{O}_2(g)\).
ii. Drinking water with \(10 \mathrm{ppm}\) fluoride is better than drinking water with \(1 \mathrm{ppm}\) fluoride.
iii. The maximum permissible concentration of lead in drinking water is \(50 \mathrm{ppb}\).
i, ii, iii
i, ii only
ii, iii only
i, iii only
Solution
Statement (i) and (iii) are correct statements whereas statement (ii) is incorrect. Its correct explanation is as follows: The drinking water with \(1 \mathrm{ppm}\) fluoride is better than \(10 \mathrm{ppm}\) fluoride.
The EPA has set maximum allowable concentration of fluorine in water at \(2 \mathrm{ppm}\) to prevent enamel fluorosis and \(4 \mathrm{ppm}\) to prevent skeletal fluorosis.