an organic pesticide was decomposed by an oxygen combustion procedure to convert the chlorine in the molecule to water soluble chloride the chloride was then precipitated as AgCl A 0.7715 gram precipitate was obtained from 500 grams of pesticide Calculate the percentage chlorine in the pesticide

0.0382%

Explanation:

Given that:

Silver chloride = AgCl

Molar mass of AgCl = (107.87 + 35.5) = 143.37 g/mol

Chlorine, Cl = 35.5

143.37g/mol of AgCl = 35.5 g of Cl

Hence, 1 g AgCl will give ; (35.5 / 143.37)

1g AgCl = 0.2476 g Cl

In 0.7715 g AgCl, ; (0.2476*0.7715) g Cl

= 0.1910 g Cl

Therefore, percentage of Cl in 500g sample:

(Mass of Chlorine / mass of sample) * 100%

(0.1910 / 500) * 100%

0.000382 * 100%

= 0.0382%

first one is the correct answer