Question

help solving problem 49

49. Silver is often extracted from ores such as K[Ag(CN),] and then recovered by the reaction 2K[Ag(CN)2Kaq) + Zn(s) 2Ag(s)+Zn(CN)2(aq) + 2KCN(aq) (a) How many molecules of Zn(CN)2 are produced by the reaction of 35.27 g of K[Ag(CN)? (b) What mass of Zn(CN)2 is produced?

  

Answer 1

49. silver is often extracted from ores such as [Ag (CN)2- and then recovered by the reaction 2% [ Az (cs), ] (aq) + Zn (9) + 2Ag (5) + Zn (CN), {ap) +2KEN () (1) How many molecules of Zn (CN)2 are produced by the reaction of 35.27 g of K [ag (en), ] ? 6 what mass of Zn (an)is produced ? Aws ? * Molecular weight of K[Ag (4),] = 199 8 Molecular weigt of Zn (CN)2 = 117.4 g 2 K 149 (C), 7 (90) + Zn ( + 2Ag (3 + Zn (N), Call) + 2ken (cy From the given balanced equation we see that a moles of K[Agen), ] reacts with Zn to produce - 1 mole of Zn (CN) 2 now, it means that 2x molecular wt of k[A2 (ew), produce 1x Molecular wt - of Zn (en) * 2x 199 gm of K[Ag (en), I produce 1x 11714 gm of Zn(a) → So, 35.27 g of keng(en), ] produce 1x 117.4 * 35.27 2x1990 .. of In (on), = 10.403g of Encant),

Now 23 1. One mole molecule of Zn (EN) contain 6.023x10 no. of molecules . 1174 g of Zn (N), contain 6.023x1023 no. of molecules - 10.40 g of Zn (CN) contain 6.023x1023 x 10.40 11704 = 5.32 x 10 no. of molecules So 1. (a) 5.32% 10% molecules of Zn (CN), are produced by the reaction of 35.27 g of KE AG (CO)_] . (6) 10.403 g of Zn (CN)2 is produced