JUHU GREI eacn addition in Data Table 1. Mass of AgzAsO4, 8 Data Table 1. Gravimetric Analysis of AgzAsO4 precipitate Aliquot Total volume 1 M Total volume in AgNO3 added, mL Na3AsO, flask, mL Initial 0.1L/100 ml 0.0 10.5 1.0 1.5 2.0 2.5 3 .0 160. 51 mL 101.02 101.53 102.05 102.56 103.07 103.57 I 104.07 0.0770847 0.154173 0.231261 0.308348 0.385435 0.462463 0.462530 0.462530 4.0

b) Using the final mass of AgaAsO4, calculate the concentration of the Na3As, in the original flask. (Show your work!) 0.462530 c) Calculate the concentration of the excess reactant (AgNO3) in the trial flask after the addition of 4.0 mL of 1 M AgNO3. (Show your work!)

and concentrated into 0.1 Lof solution. You will use gravimetric analysis to determine the concentration of NazAsO, in the solutions. To precipitate the arsenate ion, you will add a silver nitrate solution to each sample: Aso (aq) + 3Ag+ (aq) – Ag3 AsO4(s) From your measurements, you will determine the total amount of arsenic in the soil samples, then determine the concentration of arsenic in the soil. Because arsenic is present in low amounts, it is more commonly reported in ppm or ppb. Use the following equation to calculate the concentration of arsenic in ppm: gAs ppm = g soil sample Although international standards vary greatly, assume that a level of arsenic in soil over 50 ppm is dangerous.