Question

3. Balance the following redox reactions, adding H20 and H+ (or OH) as needed. Predict for each one whether the reaction would become more or less spontaneous at higher pH. Procedures for balancing redox reactions in acid or base can be found in Chapter 4.1 of our Wikibook (a) MnO4 (aq) + N2O(g) (6) Cr2O72- (aq) + S2032- (aq) c) H2O2 (aq) + HI (aq) — M n2+ (aq) + NO3- (aq) (in acid) + Cr203 (s) + SO2- (aq) (in base) 13 (aq) (in acid)

Also, can you explain why it would either become more or less spontaneous please.

Answer 1

ender 2 MnOy (99) + N₂O(g) - O +2 +5 spirit ding inceps Oxidation herita ral en upassi Reduction huma 2+ to ab Oxidation holf Moon 1995 - Mn 199) Isphe dy rise MnOu (94) + 8 4+ (99) - vide ward Mnate + 4H₂O [Balancing oxygen atoml by adding it and hol as reaction in acdie medium mende Montag + 4H2O - AL Duties om 3 MnOu 199) + 8 H+ (90) + 5e - Balancing charge on / both side by adding 0 Reduction half NaOrg) NO (98) N₂O(g) 2003 199) (Bdancing Natoms) NzO19) + 5H20 - > 2003709) + LOH D / Balancing o atoms) N2O(g) + 540 - > 2NO, 199) + 10H+ + se + Balencina charge on both Iti plyng equation ® by 8 and ® by 5 and adding there we get 5 N₂O(g) + 25 He w 1000 lar + 50Htags + you & non (99) + 64 H+199) + you & Mn2t lag) + 324011 8 Mnoy + 5 N₂O + 14 H+ (aq) - 8 Mn2+ (99) + 10 NO 3 (99) +7H2Owl I sich ome in

7 caps & SO3 cas) co GoO3(0) + Sautern (in base) t6 7 1 p Reduction Oxidations I 5₂ 0 ² 196) + 5H₂0 W Oxidation hall 503 * 199) - 5042194) $99.ing) — > 2 soul taes (Balancing the sul for atom) 17 SHOW 2002 709) / Balancing the o color "I by adding to S2O3(02) + 544044) — 2504?iors + 10 Hing D (Bodoing the toodom by adding 14 ions) 9,03712) + 5601) + 10 Dhogy > 250uay + 10h4aes + 10 Hing) As reaction is happening in basic mediom, we add of tetorn equal to number of it alors to both side of equation. e ion S205*720) + 10 04/29) — 250,co) + she Ones 5,03 1999 + 10 OH 499) = 2 soy tegy +540W + Seca Addetion of ge to babana chosge on bath the side) 101

Similarly for Reduction hall Set they > sou laat CO2 Come O3 (6) Balanced equation by performing above proudure, we get (28207* + 440 +66 > Gops (8) +80H Tags — ® (99) them an get a odding multiplying @ by 3 and ④ by 4 and adding 3520 (199) + 30 okiego 6504 188) +ISH Olej + 24€ 461 072 +16 H2Ole) +246 = > 4 68,03153 +32 0Hg). 4 6x2 0.72 +35205€¢ce) + HOL) >40BxOzly +6504?any 2014 7 (99) GHS (COM

Dol Similary for unget e H2O₂ (ac) + HI (99) 3 (ag) Oxidactia hall - O HI (aa) - I 1995 id 3 H I can I lag + 3H+ + 2e - equation (in bodic median Reduction half H₂O₂ + 2Ht as - 2 HOW T lin acidic redion) Balanced H₂O₂ (aq) + 2H+ (aq) +2e - 24010 equation 1991 On adding @ oud ® , cu get bolenad equaten. Hela cazy & 3 HI (99) - Iz (98) + thay + 21H30 90 (5) _Balanced equation are @ 8MnOy700 + 5N20 + 14 H1192) — 8 Mn?*(99) + 10 NO. 10+71 în acidic medium ☺ 4 Gee OF"cle) + 38,03%[pey+ K940 —> 4640319 + 6 504109) + 2015 agy (Basic medium) © H₂O2 (99) + 3 HI (99) Iz (99) + H lag + 2H20 W

spontaneous @ with increase in pH reaction proceeds an forward direction. (according to Le-chather prinople) backward As seen from balanud equation we get all ageous and liquid product re entropy of increase in forward direction and reaction also procuds in backward Huna reaction could become theatest spontaneous 6 with increase in pH reaction proueds in backword direction As seen from balonued equation entropy of reaction increased in backwerd dryectore Hency reechen coill become moge spontaneous @ with increase in pH reaction proceds in forward direction As seen from balonced equation entropy increases in forward direction Hacer reaction will become moro spontenoces