A sample of pressure-treated wood weighing 0.3245 g was dissolved in concentrated nitric acid to convert all of the arsenic to arsenate. The solution was diluted 10 times and excess silver added to precipitate silver arsenate (Ag3AsO4), which was collected dried and weighed. If the mass of the precipitate was 0.0453 g what is the percentage of arsenic in the wood?
a) 2.26
b) 9.03
c) 22.5
d) 2.24
e) 3.01