Question

4.51 Which element is , and which is reduced in the fol reactions (a) N 3 (s)+3H 2 (s) 2NH 3 (s) (b 3 le(NO 1 ) 2 (a 1 )+2 M(s) 3 Fe(N)+2 Al(NO 1 ) 1 (aq) ( PbS(s)+4 H 3 O 2 (aq) PrSO 4 (s)+4H 2 O(l)

4.51 Which element is oxidized, and which is reduced in the fol- lowing reactions? (a) N2(g) + 3H2(8) — 2 NH3(g) (b) 3 Fe(NO3)2(aq) + 2 Al(s) — 3 Fe(s) + 2 A1(NO3)2(aq) (c) C12(aq) + 2 Nal(aq) Iz(aq) + 2 NaCl(aq) (d) PbS(s) + 4H2O2(aq) PbSO4(s) + 4H2O(1)

Answer 1

Sol: The process in which loss of electrons takesplace is called as oxidiation and in this process oxidation number of substance increases takes (2) where as em reduction electrons gain of place and in which oxidation nooof a substance decreases. Now o reduction -3 Ng & bé 2N & gain of es C® O.No decreased 3 Hg - 6HØt 6 loss of es, oxidation (0) increased Oe No oxidised . Na -reduced, Hq O.No increased loss of ē (0) low of +2 (6) 3 Fe(NO3 (NO3)2 2Al(s) 3 fe + 2 A(NO3), car) t (S) gain of es (R) o. No decreased +2 Fe the res Fes (gain of e) reduction 3% cen +3 Al (loss of ) oxidation o x Al 3ē (5) oxidised Fe(NO3)2 - reduced, Afsy

dotze acean acê (gain of e) reduction car) to sed (reduction) sol el" a.NO I Ig pel + 2 Closs of ē) oxidation ex) M I" oxidation no. Increased da al reduced oxidised. En (ه) +6 -2 pbs pbsoy + 8 (loss of =oxidation sol ! so. No increased Coxidation) Tog Наб 2 (gain of e = Reduction u o oxidation number decreased pbs = oxidised cês not balanced) H2O2 reduced Note!" O.NO oxidation number. ē = electron