Question

1. Which metal can reduce Ni2+ ions but not Fe2+ ions? Cd²⁺，Cr，Sn²⁺，Sn，Cd

2.Which species can oxidize Sn but not Fe? Ni，Ni²⁺，Pb²⁺，Cd，Pb

1.68 1.51 1.50 1.09 1.00 0.96 0.95 FAO) + 2 H,0,1a) + 2H(aq) + 2e PO4 + 4H"(aq) + S0,00) + 2€ Mno. (aq) + 4H(aq) + 3e Mno,aq) + 8H(aq) + 5e Au?+ (aq) + 3€ PbO (8) + 4H(aq) + 2 Cl@) + 2 Cr,0,?" (aq) + 14 H*(aq) + 6e 0,(@) + 4H(aq) + 4e MnO (s) + 4H+ (aq) + 2 103" (aq) + 6 H(aq) + 5e Br.) + 2e Volaq) + 2 H(aq) + NO, (aq) + 4H(aq) + 3e CIOC) + 02(g) + 4H* (aq) + 2e Ag laq) + e Fe (aq) + 0,0) + 2H(aq) + 2e Mno." (aq) + e 8) + 2e Cuaq) + e 0,(@) + 2H2O() + 4 Cu? (aq) + 2 SO, (aq) + 4H(aq) + 2 Craq) + e Sn+ (aq) + 2 e 2 H(aq) + 2e Fe3+ (aq) + 3e Pb?" (aq) + 2 Son (aq) + 2e Ni+(aq) + 2 Of (aq) +20 24,0(!) + 2e Fe(aq) + 2e Cr(aq) + Cr(aq) + 3e Zn2+ (aq) + 20 2 H,00) + 2 Mn(aq) + 20 Ad(aq) + 3e Mg²+ (aq) + 2e Naaq) + 2F (aq) - 24,00 PbSO4 + 2H2011) - MnO,(s) + 2H2011 Mn? (aq) + 4H,00 As Pb(aq) + 2 H,00) - 2 Cr(aq) - 2 Cr3+ (aq) + 7H2011) 2,00) - Mn (aq) + 2H,00 (aq) + 3H2011) - 2 Braq - VO2(aq) + H200) - NOW) + 2 H2011) - C10 (aq) 2H2O(l) Agisi - Fe(a) - Hy0(aq) - Mno-ag) - 2r(a) Oulsi - 4 OH(aq) - Cups - HSOfaq) + H2001) - Cu (aq) - Sn (a) - H ) Feis) - Pb(s) - Sns - Nis - Cols - Hal@) + OH(aq) > Fe(s) - Craq) - Cr(s) - Zn(s) H) + 2OH(aq) - Mnis) Al(s) - Mg(s) Nas E = 0.82V (pH = 7) 0.80 0.77 0.70 0.56 0.54 0.52 0.40 0.34 0.20 0.16 0.15 -0.036 -0.13 -0.14 -0.23 -0.40 E -0.41V (pH -0.45 -0.50 7)

Answer 1

the metal having more - ve standard reduction potential, more will be its reducing power.

or lower the reduction potential of a metal, greater will be its tendency to reduce ions having greater reduction potential.

reverse, Any ion can oxidize a metal, if reduction potential of that ion is greater(+ve) than reduction potential of that metal.

1)the metal which can reduce Ni2+ but not Fe2+ is Cd.

it is because its reduction potential is Cd is lower than Ni2+, so it can reduce Ni2+ ion. But it has higher reduction potential tha Fe 2+.

2) the species which can oxidize Sn but not Fe is Pb2+.

because its reduction potential is greater than reduction potential of Sn2+, but lower than Fe3+.