precipitation problem

[BodybldgDoc]

If all of the chloride in a 5 gram sample of an unknown metal chloride is precipitated as AgCl with 70.9mL of 0.201 M AgNO3, what is the percentage of chloride in the sample?
A. 50.55%
B. 20.22%
C. 1.43%
D. 10.10%
E. none of the above

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[Lonely Sol]

When I did it, I got like 7%, so i gues the answer is E, is it true.

(i am not sure on this one, but it should be E)

 

[REH]

Maybe I'm missing something, but here's how I would go about calculating this.

70.9 mL * 1L/1000 mL * 0.201 mol AgNO3/L * 1 mol Ag+/ 1 mol AgNO3 * 107.8 g / 1 mol Ag+ * 1/5.00 G * 100 = 30.7 %

Answer: E, none of the above.

If all of the chloride in a 5 gram sample of an unknown metal chloride is precipitated as AgCl with 70.9mL of 0.201 M AgNO3, what is the percentage of chloride in the sample?
A. 50.55%
B. 20.22%
C. 1.43%
D. 10.10%
E. none of the above

 

[BodybldgDoc]

I cannot confirm what the correct answer would be but the answer to the problem is is E none of the above. From the looks of it, i think REH found the percentage of Ag instead of Cl in the sample. So,
1-.307=.693 or 69.3% of Cl in the sample after precipitation. What do ya think?

 

[REH]

Oops! You're right. Thanks for catching that.

 

[BodybldgDoc]

no problem REH. thanks for taking the time to solve it.