Question

0.254g of lead 2 ethanoate on adding K2CrO4 solution gave 0.130g of lead 2 chromate precipitate. What is the percentage composition of Pb in the organic salt

Answer 1

Step-by-step explanation:

Molecular formula of lead II chromate = PbCrO₄

Molecular weight of lead II chromate = 323 g

Atomic weight of Pb = 207

323 g of lead II chromate contains 207 g of lead

.130 g of lead II chromate contains 207 x .130 / 323 g of lead

= .083 g

This mass of Pb must have come from organic salt .

.254 g of organic salt contains .083 g of Pb

100 g of organic salt contains .083 x 100 / .254 g of Pb

= 32.67 g

Required percentage composition = 32.67 % .