Page 1336 - Chemistry--atom first
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1326 Answer Key
5. Al is used because it is the strongest reducing agent and the only option listed that can provide sufficient driving force to convert La(III) into La.
7. Mo
9. The CaSiO3 slag is less dense than the molten iron, so it can easily be separated. Also, the floating slag layer
creates a barrier that prevents the molten iron from exposure to O2, which would oxidize the Fe back to Fe2O3. 11. 2.57%
13. 0.167 V
15. E° = −0.6 V, E° is negative so this reduction is not spontaneous. E° = +1.1 V
17. (a) (b)
(c)
(d)
(e) (f)
19. (a)
(b)
(c) In acid solution between pH 2 and pH 6, forms which is in equilibrium with dichromate ion. The reaction is
At other acidic pHs, the reaction is (d)
(e)
(f)
21. (a) (b)
(c)
(d)
(e)
(f)
(g)
23. As CN− is added,
As more CN− is added,
25. (a) Sc3+; (b) Ti4+; (c) V5+; (d) Cr6+; (e) Mn4+; (f) Fe2+ and Fe3+; (g) Co2+ and Co3+; (h) Ni2+; (i) Cu+
27. (a) 4, [Zn(OH)4]2−; (b) 6, [Pd(CN)6]2−; (c) 2, [AuCl2]−; (d) 4, [Pt(NH3)2Cl2]; (e) 6, K[Cr(NH3)2Cl4]; (f) 6,
[Co(NH3)6][Cr(CN)6]; (g) 6, [Co(en)2Br2]NO3 29. (a) [Pt(H2O)2Br2]:
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