Question

The percent chloride in an unknown sample may be determined by gravimetric methods. Suppose a 0.6789g sample of an unknown chloride sample was dissolved and AgCl is precipitated by adding AgNO3 solution. The precipitate was filtered, ignited, and found to weigh 0.3333g. What was the percent chloride in the sample?

Answer 1

Answer: The percent chlorine in the sample is 12.08 %.

Step-by-step explanation:

We are given:

Mass of AgCl precipitated = 0.3333 g

Molar mass of AgCl = 143.32 g/mol

Molar mass of Chlorine atom = 35.45 g

In 1 mole of AgCl, 1 mole of chlorine atom is present.

In 143.32 grams of AgCl, 35.45 g of chlorine atom is present.

So, in 0.3333 grams of AgCl, the mass of chlorine present will be =
`(35.45)/(143.32)* 0.3333=0.082g`

To calculate the percentage composition of chlorine in sample, we use the equation:

`\%\text{ composition of chlorine}=\frac{\text{Mass of chlorine}}{\text{Mass of sample}}* 100`

Mass of sample = 0.6789 g

Mass of chlorine = 0.082 g

Putting values in above equation, we get:

`\%\text{ composition of chlorine}=(0.082g)/(0.6789g)* 100=12.08\%`

Hence, the percent chlorine in the sample is 12.08 %.