Question

A 3.7514 g sample of copper(II) nitrate is dissolved in water and 2.000 g of copper(II) arsenate (Ksp = 7.6 x 10-36) is added so that the total solution volume is exactly 1 L. What is the concentration of the arsenate ion in the solution (assuming the arsenate ion does not react with water)? (b) If the arsenate ion does react with water, write the overall principal chemical equation and determine K. (Arsenic acid is triprotic: Ka1 5.8 x 10–3 ; Ka2 1.1 x 10–7 ; Ka3 3.2 x 10–12

Answer 1

The objective is to calculate the following question Ans Given that, mol of copper ll) nitrate added in the solution - mass /molar mass 63.751491(187.56 g/mol), 50.020 mol. mol of copper (11) arsenate added a = 2.000 g/C468.48 g/mol) -0.00427. concentration of copper (11) nitrates C copper (11) nitrate] = 0.020 mollil. 50.020 M. concentration of copper (11) arsenates [Copper (11) arsenate] =0.00427 mol/l = 0.00427 M.

In solution Copper (11) nitrate felly dissociates into ions as follows: Cu(NO3)2 (s) cut (aq) + 2NO3 (aq). So that, [cult] = [cu(NO3)2) = 0.020 M. copper (11) arsenate partially dissociates in Solletion due to its very low solubility as follows: Cu3(ASO4)2 (5) 3 Cu2+(99)+2 Ason (aq). Ksp = 7,6x1536 = [curt33 [asou cauzt] =0.020 M (much higher solubility for copper (11) nitrate). Thus, 7.641626 -[cuft j(ASCE? 3* = 6.02 ml) [Aschaj er, CASO4 J3 = (.6216369760.cemy ev, [ASCE? =(7.6X1636)/(B x166)

(Ascos 9.5x1031 [Asour] = 59.511631 (Asos] = 19,747x15m Asou +HO = H2 AsO4 + 3OHT (principal chemical equation). K = Kw/ Kas =(1.0%1694)/(3.2x512) K 43.125x103) O