What is the concentration of bromide present in a 0.659 M. solution of CaBr2

[um0123]

Homework Statement

The arsenic in a 1.42 g sample of pesticide was converted to AsO43- by suitable chemical treatment. It was then titrated using Ag+ to form Ag3AsO4 as a precipitate. If it took 33.7 mL of 0.113 M Ag+ to reach the equivalence point in this titration, what is the mass percentage of arsenic in the pesticide?

Homework Equations

im not sure

The Attempt at a Solution

I just need a way to get the ball rolling, this is a questions for my AP Chemistry summer review and i haven't taken chemistry since sophomore year (im going to be a senior when school starts in two days) and i forgot the equations i need to solve this kind of stuff.

 

[Borek]

First - calculate number of moles of arsenate from the titration reaction stoichiometry.

http://www.titrations.info/titration-calculation

Second - how many moles of arsenic per 1 mole of arsenate? How much arsenic in teh sample?

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