Question

Questions 22-24 refer to the following information. A group of students was asked to recover Cu(s) from a blue-green aqueous solution containing an unknown concentration of Cu (aą). The students took a 100.0 ml sample of the solution and added an excess of 1.0 M Na PO(aq), causing the Cu?(aą) to precipitate as Cu,(PO,)(s), as shown in step I below Step l Blue-green Cu (aq) Colorless Blue-green Cu3(PO)2(5) 10 M Na PO (a 3 Cu(ag) 2 Na,PO, (ag)Cu(P0))+ 6 Na (ag) The Cu;(PO,)(s) was filtered, dried, and weighed. Then the Cu,(PO,)2(s) was dissolved in a 3.0 MHCKaq) solution, as shown in step 2 below. Step 2 Blue-greern CuCl (aą)+ H,PO(aa) Blue-greern Cu3(PO)2() Colorless 3.0 M HCKaą) 3 CuCllag)+2 H,PO(aq) Cu (PO)2(s)+6 HCI(aq) The students added a strip of Zn(s) to the solution to recover the Cu(s), as shown in step 3 below. Step 3 Colorless ZnCl (aa) Brown Cu(s) Silver-colored Zn(s) Blue-green CuCl (aq) Cuci(ag) Znts) Cu(s) + ZnCI (ag) Zn(s) Finally, the Cu(s) was filtered, dried, and weighed.