Farmatsevtika in st it u t I talabalari uchu n 0 ‘quv adabiyoti
H + + 5e = M n 2+ + 4 H 20 137
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8 H + + 5e = M n 2+ + 4 H 20 137 2- qoida. O k sid lo v ch i ta rk ib id a g i o rtiq c h a k islo ro d n ey tral va ish q o riy m u h itd a suv m o le k u la si b ila n birik ib gid ro k sid io n in i hosil qilad i va qay tarilad i: [O] + H 20 + 2e = 2 O H - M n 0 4 ~ + 2 H 20 + 3 r = M n 0 2 + 4 O H - 3-qoida. Q ay taru vchi kislotali va neytral m u h itd a yetishm agan k islo ro d n i su v d an olib o k sid la n a d i va v o d o ro d io n in i h o sil qiladi: H 2 0 —2e = [O] + 2 H + S 0 23 + H 2 0 - 2 e = S 0 4+ 2 H 4-qoida. Q a y ta ru v c h i k u c h li ish q o riy m u h itd a y e tish m a g a n k islo ro d n i g id ro k sid io n id a n o lib o k sid lan ad i va suv m o le k u la sin i hosil q ilad i: 2 O H - - 2e = [O] + H 20 S O 2- + 2 0 H “ - 2C - = S O f + H 20 Г + 6 O H - — 6 e = IO J + 3 H 20 Misol: K M n 0 4 + N a , S 0 3 + H 2 S 0 4 -> M n S 0 4 + N a 2 S 0 4 + + K 2 S 0 4 + H 20 B u reaksiya n a tija sid a kaliy p e rm a n g a n a tn in g p u s h ti rangi o 'c h ib , e ritm a rangsizlanadi. O k sid lan ish -qaytarilish reaksiyasida qatnash ayo tgan ionlarni alo h id a ajratib, reaksiya sxem asini yozam iz: M n O ; + S 0 3 + H + -> M n + S O f + ( • ) O k sid lo vchining q ay tarilg an va q a ta ru v ch in in g oksid lan g an in i k o 'rs a tu v c h i y a rim rea k siy ala rn i yozam iz: M n O ; -> M n ( 1 ) S O 2- S O 2" (2) (1) Y arim reaksiyaga 1- q o id an i va (2) yarim reaksiya 3-q o id an i q o ‘llab , y u q o rid ag i rea k siy ala rn i q u y id ag ic h a y o zam iz: M n O ; + H + -> M n + H 20 S O f + H 20 -> S 0 2“ + 2 H + 138 B u r e a k s iy a la r d a g i k o 'r s a t k i c h l a r n i te n g lik is h o r a s ig a a lm a s h tiris h u c h u n d a stla b y a rim reak siy alarn in g o 'n g va c h a p to m o n la r id a g i k islo ro d va v o d o ro d a to m la r i s o n in i, s o 'n g ra z a ry a d la r so n in i te n g la sh tira m iz . Z a ry a d la r so n in i ten g la sh tirish u c h u n y a rim reak siy an in g o 'n g tara fid a g i z a ry a d la r y ig 'in d isin i c h a p tarafg a teskari ish o ra b ila n o 'tk a z ib , c h a p tarafdagi zary ad lar y ig 'in d isin i h iso b lay m iz. Y ig 'in d i c h a p tara fg a q a n c h a e le k tro n q o 's h is h yoki ayrish k e ra k lig in i k o 'rsa ta d i: M n 0 4 “ + 8 H + + 5e = M n + 4 H 20 2 S O f + H 2 0 - 2 e = S 0 f + 2 H + 5 R eaksiya ten g la m a sin i tu z is h u c h u n oksidlovchi q ab u l qilgan va q a y ta ru v c h i y o 'q o tg a n e le k tro n la r so n in i ten g la sh tiru v c h i en g k ichik koeffitsiyentlam i aniqlaym iz. T o p ilg an koeffitsiyentlarga ya rim reak siy alarn in g o ld in c h a p ta ra fla rin i, s o 'n g ra o 'n g tara fla rin i k o 'p a y tirib , h a d m a - h a d q o 's h ib yozam iz: 2 M n O ^ + 16 H + + 5 S O f + 5 H 20 = 2 M n + + 8 H ?0 + 5 S 0 f + 10ҒГ O 'x s h a s h io n la rn i q is q a rtirib o k sid la n is h -q a y ta rilis h re a k siy asin in g ion te n g la m a sin i h o sil qilam iz: 2 M n O f + 5 S O j" + 6 H + = 2 M n + 5 S O f + 3 H 20 Io n te n g la m a d a n m o le k u ly a r te n g la m a n i hosil qilish u c h u n , io n te n g la m a n in g c h a p q ism ig a h a r b ir k a tio n v a a n io n g a m o s ke la d ig an a n io n va k a tio n n i q o 's h a m iz va m a z k u r io n la rn i shu m iq do rda reaksiyaning o 'n g qism iga h a m q o 'sh ib yozam iz. S hun d an s o 'n g io n la rn i q o 's h ib m o le k u la la rg a b irla sh tira m iz : 2 M n O ^ + 5 S O j~ + 6 H + = 2 M n + 5 S O f + 3 H 20 2 K + + 1 0 N a + + 3 S O f - 2 S O f + 1 0 N a+ + 2 K + + SO ---1------------------------------------------------------------------------------ 2 K M n 0 4 + 5 N a 2S O j + 3 H 2 S 0 4 = 2 M n S 0 4 + 5 N a 2 S 0 4 + + K 2 S 0 4 + 2 H jO 139 S h u n d a y q ilib , o k sid la n ish -q a y ta rilish reaksiyasin ing to 'liq m o le k u ly a r te n g la m a s in i h o sil qildik. ERITM A M U H IT IN I OK SIDLANISH-QAYTARILISH REAKSIYASINING B O R ISH IG A TA’SIR I E r itm a la r d a o k s id la n is h - q a y ta rilis h re a k s iy a la ri k islo ta li, neytral yoki ish qo riy m u h itd a b o rish i m u m k in . E ritm a n in g m u h iti a to m la r o k s id la n is h d a r a ja la r in in g o 'z g a r is h ig a k a tt a t a ’sir k o 'rsa ta d i. M a sa la n , p e rm a n g a n a t io n in in g ( M n O ^ ) q ay tarilish m ah su lo tlari m u h itg a b o g 'liq h o ld a tu rlic h a b o 'lish i m u m k in . H + 2+ ------------- ► M n rangsiz e ritm a M n 0 7 ---------- 1+ p u sh ti ran gii e ritm a H 20 O H -► M n 0 2 q o 'n g 'ir c h o 'k m a M n 0 4 yashil rangii e ritm a M n O ^ ioni k islotali m u h itd a M n 2+ ga, n e y tra l m u h itd a M n 0 4 ga, ish q o riy m u h itd a M n 0 4_ ga q a d a r q ay tarilad i. E ritm alarga kislotali m u h it berish u c h u n , o d a td a , sulfat kislota ish latilad i. N itra t k islo ta k am ish la tila d i, c h u n k i n itra t k islo ta o k sid lo v ch i, x lo rid k islo ta esa q a y ta ru v c h ilik xususiy atiga ega. Ish q o riy m u h it h o sil qilish u c h u n kaliy va n a triy g id ro k sid lari ishlatiladi. M isol: K M n 0 4 va K N 0 2 nin g kislotali s h a ro itd a o k sid la n ish - q a y ta rilish rea k siy asin in g io n sxem asi q u y id a g ic h a b o 'Ja d i: M n O ; + N 0 2 + H + -> M n + N O J + H 20 + ....... K islotali s h a ro itd a o k sid lo v ch i q a y ta rilish in i va q a y ta ru v c h i o ksid lan ish in i hiso bga olib, b irin ch i va u c h in c h i q o id alarn i q o 'lla b y a rim re a k siy ala rn i yo zam iz: 140 2+ M n 0 4 + 8 H + + 5e = Mn+ 4 H 20 N 0 2 + H 2 0 - 2 e - N 0 7 + 2 H + 5 2 2 M n 0 4 + 16 H + + 5 N 0 2 + 5 H 20 = 2 M n + + 8 H 20 + 5 N 0 J + 10H + H osil b o 'lg a n io n te n g la m a sin in g c h a p va o 'n g qism id ag i b ir xil io n va m o le k u la la m i q isq a rtirib , h o sil b o 'lg a n ko effitsiy en t- la m i m o le k u ly a r te n g la m a g a yozam iz: 2 K M n O + 5 K N 0 2 + 3 H 2 S 0 4 = 2 M n S 0 4 + + 5 K N 0 3 + K 2 S 0 4 + 3 H 20 N e y tra l m u h itd a : M n 0 4 + S O f + H 20 -> M n 0 2 + S O f + O k sidlov ch i u c h u n ik k in c h i va q a y ta ru v c h i u c h u n u c h in c h i q o id a n i q o 'lla b y a rim reak siy alarn i yo zam iz: 2 M n 0 4 + 2 H 20 + 3e = M n 0 2 + 4 0 H ~ + SO 3 2- + H 20 - 2e = S O f + 2 H + 2 M n 0 4 + 3 S O f + 7 H 20 = 2 M n 0 2 + 3 S O f + + 8 0 H “ + 6 H + yoki to 'liq m o le k u ly a r h o ld a yozish u c h u n ion ten g la m a n in g c h a p va o 'n g qism iga m o s k elad ig an k atio n va a n io n la m i q o 'sh a m iz : 2 K M n 0 4 + 3 N a 2 S 0 3 + H 20 = 3 N a 2 S 0 4 + Ish q o riy m u h itd a : M n 0 4 + S O 3 + 2 M n 0 2 + 2 K O H + O H S O f + 2 M n O f O ksidlovchi u c h u n q o id a ish la tilm a y d i, c h u n k i kislorod 141 a to m la ri so n i te n g . Q a y ta ru v c h i u c h u n to 'r tin c h i q o id a n i q o 'lla b y arim rea k siy ala rn i y o zam iz: + S O f + 2 0 H ~ - 2e = S O f + H 20 1 МПО 4 + le = M n O f 2 K M n 0 4 + N a 2 S 0 3 + 2 N a O H = N a 2 M n 0 4 + + K 2 M n 0 4 + N a 2 S 0 4+ H 20 B a ’z id a o k s id la n is h - q a y ta r ilis h r e a k s iy a s in in g b o r is h ig a e ritm a n in g ko nsen tratsiy asi va h aro rati h a m t a ’sir qiladi. M asalan, xlo rn in g su y u ltirilg a n ish q o rla r b ila n reaksiyasi past h a ro ra td a g ip o x lo ritla r va x lo rid la r hosil b o 'lish i b ila n k ech ad i: C1 2 + 0 H - > C 1 0 + С Г + C l 2 + 4 O H - 2e = 2 CIO" + 2 H , 0 C l, + 2e = 2 С Г 2 C 1 , + 4 0 H " = 2 C I 0 - + 2 H , 0 + 2 C l“ C l, + 2 N a O H = N a C 1 0 + N a C l f H , 0 Shu reaksiya k o n se n trla n g a n ish q o r ish tiro k id a, 100°C da olib b o rilg a n d a x lo ra tla r hosil b o 'lad i: C l, f O H 100°C C l, r l 2 ( ) H C l, 2c 2 Cl n o : h C i 2 C IO , - 6 H O 3 C l, + 6 0 1 ! = C I O 5 Cl 4 H : 0 M e ta lla r o k sid lo v ch ilik xossasiga ega bo u n n kislo talar bilan reaksiyaga k irish g a n d a k islota a n io n lari Ь н ч o i--id lo , J i i Iv m tu z hosil q ilu v chi sifatid a q a tn a sh a d i 1-misol. Magniv metallisn ko‘ rr! v.ilf-ir l:1 t a ’sir ettirsal Vi_ i '• = л I _ 1 I A ' S 0 4 a n io n in in g b ir qism i m ag n iy n i oksid lash g a, b ir qism i esa u b ila n tu z h o sil qilishga sarflan ad i: (oksidlashga) (tuz hosil qilishga) 2 - m isol. M isn in g su y ultirilgan n itra t k islo ta b ila n t a ’sirlanish reak siy asin i yozing: C u + N O J + H + -► C u + N O + Y a rim re a k siy a la rn i y o z ib , u la m i k o effitsiy en tlarg a k o ‘p a y - tirib q o ‘shib y o z a m iz: 3 CU + 2 NO 3 + 8 H+ = 3 C u 2+ + 4 H 20 + 2NO M o le k u ly a r h o latd ag i reaksiya te n g la m a sin i yozay o tg an d a m is n itra tin i h o sil q ilish g a o ltita n itra t a n io n id a n k erak . U n d a : 3 Cu + 8 N O J + 8 H + = 3 Cu-t- 2 N O + 4 H20 + 6 N O J 3C u + 8 H N O 3 = 3 Cu (N 0 3 )2 + 2 N O + 4 H 20 D e m a k , b u rea k siy ad a o k sid lo v c h i H N 0 3, reaksiya n a tija sid a NO ga q a y ta rilis h b ila n b ir q a to r d a tu z h osil q ilish d a h a m q a tn a s h a y a p ti. K o m p le k s b ir i k m a l a r h a m o k s id la n is h - q a y ta r ilis h r e a k siy a la rid a q a tn a s h is h i m u m k in : M g° - 2 e = M g ?+ + s o f + 4 H + + 2 e = S 0 2 + 2 H 20 1 M g + S O f + 4 H + = M g 2+ + S 0 2 + 2 H 20 M g h H 2 S 0 4 + H 2 S 0 4 = M g S 0 4 + S 0 2 + 2 H 20 1 - m iso l. [C o ( N H 3) J ( 0 H ) 2+ H 2 0 2 - » [ C o ( N H 3) J (O H ) 3 143 B u sx e m a u c h u n y a rim re a k s iy a la rn i y o z a m iz va u la rn i q o ‘sham iz: [Co (N H 3 ) J 2+—1 e -> [Co (N H 3),]3+ + H ,0 2+ 2 e 2 OH 2 ‘ l 2 [C o ( N H 3 ) J 2+ + H 2 0 2 = 2 [C o ( N H 3)6] 3+ + 2 O H " H osil b o 'lg a n ion ten g la m a n i m o lek uly ar tenglam aga o 'tk az ish u c h u n m o s k e la d ig an gid ro k sid io n in i q o 's h a m iz : 2 [C o ( N H 3)6]2+ + H 2 0 2 = 2 [C o ( N H 3 ) J 3+ + 2 O H ~ 4 O H ’ 4 O H _ 2 [C o ( N H 3) 6 ( O H ) , + H 2 0 2 = 2 [C o ( N H 3)6] ( O H ) , 2 - misol. [F e ( C N ) J 4- + H 2 0 , + H + -► [F e ( C N ) 6]3“ + H , 0 O k sid lo v ch i va q ay ta ru v ch i u c h u n y a rim rea k siy ala rn i yozib, u la m i q o 's h a m iz : H 2 0 2 + 2 H + + 2e = 2 H 20 + 1 [F e ( C N ) J 4-— 1ё = [ F e ( C N ) , ] 3 H , 0 , + 2 H + + 2 [F e ( C N ) 6]4_ = 2 [F e ( C N ) 6] J- + 2 H 20 H osil b o 'lg a n ion ten g la m a g a m os kelgan k ation va an io n la rn i q o 's h ib m o le k u ly a r te n g la m a n i hosil qilam iz: H , 0 , + 2 [F e ( C N ) 6]4“ + 2 H + = 2 [F e ( C N ) 6] 3" + 2 H , 0 8 K + S O f 8 K + S O f H , 0 , + 2 K ,[ F e ( C N ) J + H 2 S 0 4 = 2 К Л Ғ е ( C N ) J + + K 2 SO., + 2 H , 0 K e ltirilg an ikkala m iso ld a h a m k o m p lek s hosil q ilu v c h in in g , y a ’ni m ark a ziy a to m n in g o k sid lan ish darajasi o 'z g a rm o q d a . 1 4 4 MURAKKAB OK SIDLANISH-QAYTARILISH REAKSIYALARI O ksidlanish-qaytarilish reaksiyasida ikkitadan ortiq elem ent ato m la ri y o k i ion lari ish tirok etib o k sid lan sa y o k i qa yta rilsa , m urakkab oksidlanish-qaytarilish reaksiyasi deyiladi. M asalan : As 2 S 3 ga k o n s e n trla n g a n H N 0 3 t a ’siri +3 - 2 +5 A s 2 S 3 + H N 0 3 H 3 As 0 4 + H 2 S 0 4 + N 0 2 + H 20 O ksidlovchi va q a y ta ru v ch ilam i a n iq la b , ularning qabul qilgan va b e rg a n e le k tro n la r so n in i te n g la s h tiru v c h i ko effitsiy en tlarin i to p a m iz . (Q a y ta ru v c h ila r A s +3 va S-2, o k sidlovchi N +5). O k sid lan ish ja ra y o n i: 2 A s+ 3 —4 e - 3 S ~ 2 - 2 4 e < Q a y ta rilish ja ra y o n i: N +5+ 1 ё -> N 2 As - 3 S + +5 - 28c +4 1 28 R eaksiyaning elek tro n balans sxem asidan k o ‘rinib turibdiki, b ir m olekula As 2 S 3 ni oksidlash u c h u n 28 m olekula H N 0 3 sarflanadi. Bu koeffitsiyentni reaksiyaga olingan H N 0 3 oldiga q o 'y ib , so ‘ng reaksiyaning o ‘ng to m o n id a hosil b o 'lg an m o d d ala r tenglashtiriladi: a) A s 2 S 3 + 28 H N 0 3 —> H 3 A s 0 4 + H 2 S 0 4 + N 0 2 + H 20 b) As 2 S3+ 28 H N 0 3 = 2 H 3 A s 0 4 + 3 H 2 S 0 4+ 2 8 N 0 2 + 8 H 20 2- misol. Q o ra p o ro x n in g yonishi quyidagi reaksiya tenglam asi b ila n ifodalanadi: C° + K N 0 3 + S° n 2 + C 0 2+ K 2 s O k s id la n is h d a r a ja s i o r ta y o t g a n e le m e n t a to m la r i ( C ) q a y ta ru v c h i, k a m a y a y o tg a n e le m e n t a to m la ri ( N +\ S ° ) o ksidlov- ch ilard ir. Oksidlanish ja ra y o n i: C — 4 e -> C +4 +5 Q aytarilish ja ra yo n i: 2 N + lOe S° + 2 e -♦ S " 2 N 2 4 12 145 E le k tro n b a la n s sxem asi b o 'y ic h a a n iq la n g an koeffitsiyentlam i reaksiya te n g la m a s ig a q o 'y ib reak siy a te n g la sh tirila d i: 3 C + S + 2 K N 0 3 = N 2 + 3 C 0 2 + K 2s E r it m a d a b o r a d i g a n m u r a k k a b o k s id l a n is h - q a y ta r i l is h reaksiyalari y a rim rea k siy ala r usuli b ila n te n g la sh tirila d i. M iso l: A s 2 S 3 k o n s e n trla n g a n H N 0 3 t a ’sirid a ok sid lan ad i: A s 2 S 3 + H N O j -> H 3 A s 0 4 + H 2 S 0 4 + N 0 2 yoki rea k siy an in g io n sxem asi: A s 2 S 3 + H + + N O 3 -> H 3 A s 0 4 + S O f + N 0 2 As 2 S 3 — q a y ta ru v c h i, N O ^ — o k sid lo v ch i. B u rea k siy ad a b ir m o le k u la A s 2 S 3 ik k ita H 3 A s 0 4 va u c h ta 4 SO 4 io n la rin i h o sil qiladi: A s 2 S 3 -> 2 H 3 A s 0 4 + 3 S O f Kislotali m u h itd a qaytaruvchi yetish m ayotgan kislorodni suv m olekulasidan oladi (3- qoida). Ikkita H 3 A s 0 4 hosil qilish u ch u n 8 m olekula suv, 3 ta S O f ionini hosil qilish u c h u n esa yana 12 ta suv m olekulasi kerak. D em ak , yarim reaksiya u c h u n ja m i 20 m olekula suv kerak b o 'lib , reaksiya natijasida 34 ta vodorod ion ni hosil bo'ladi. A s 2 S 3 + 20 H : 0 - 28e = 2 H 3 A s 0 4 + 3 S O f + 34 H + K islotali s h a ro itd a N 0 3 ioni N 0 2 g a o 'ta d i: N O ^ + 2 H + + l r -» N 0 2 + H 20 Ik k a la y a rim r e a k s iy a la rn i k o e ff its iy e n tla r g a k o 'p a y tir ib q o 's h ib y o zam iz: A s 2 S 3 + 20 H 20 - 28 e = 2 H 3 A s 0 4 + 3 S O f + 34 H + N 0 3 " + 2 H + - le = N 0 2 + H 20 1 28 A s,S 3 + 28 N O J + 28 H + = 2 H 3 A s 0 4 + 3 S O f + 6 Н Ч + 28 N 0 2 + 8 H 20 146 R eaksiya ten g la m a sin in g c h a p va o ‘ng tara fla rid a g i b ir xil io n va m o lekulalarini qisqartiram iz. H osil b o 'lg an koeffitsiyentlam i m o le k u ly a r te n g la m a g a q o ‘yam iz: A s,S , + 28 H N O , = 2 H ,A s 0 4 + 3 H , S 0 4 + 28 N O , + 8 H ,0 . 2 3 3 3 4 2 4 2 2 O K SID LO V C H I VA QAYTARUVCHINING EKVIVALENTI O k sid lo v ch i va q a y ta ru v c h ila r d o im o o ‘z a ro ek v iv alen t m iq d o rd a reaksiyag a kirishadi. O k s id lo v c h in in g e k v iv a le n ti d e b , o k s id la n is h - q a y ta rilis h reaksiyasi n atijasid a o k sid lov ch in in g qabul qilgan 1 m ol e le k tro n - lariga to ‘g ‘ri keladigan m iqdoriga aytiladi. Oksidlovchining ekvivalent m assasini to p ish u c h u n u n in g m o ly a r m assasini shu reaksiyada ok sid lo v c h i q a b u l q ilg an e le k tro n la r m iq d o rig a boMish k erak. Q a y ta ru v c h in in g e k v iv a le n ti d e b , o k s id la n is h - q a y ta rilis h re a k s iy a s id a q a y ta ru v c h in in g b e rg a n 1 m ol e le k tro n ig a te n g keladigan m iqdoriga aytiladi. Q aytaru v ch in in g ekvivalent m assasini to p ish u c h u n u n in g m o ly ar m assasin i sh u reaksiyada q a y ta ru v ch i b e rg a n e le k tro n la r m iq d o rig a b o 'lis h kerak. M iso l: F e 2+ + C r 2 0 2- + H + = F e 3+ + C r 3+ + F e 2+ — e = F e 3+ 6 C r 2 0 7_ + 1 4 H + + 6 e = 2 C r 3+ + 7 H 20 1 6 F e 2+ + C r 2 0 2” + 14 H + = 6 F e 3+ + 2 C r 3+ + 7 H 20 M o le k u ly a r h o ld a yozsak: 6 F e S 0 4 + K 2 C r 2 0 7 + 7 H 2 S 0 4 = 3 F e 2 ( S 0 4 ) 3 + + C r 2 ( S 0 4 ) 3 + K 2 S 0 4 + 7 H 20 O k sid lo v c h in in g ekv iv alent m assasi: г M 294 , , e k 2 c q o 7 = “ 6 = “ 6 “ g / Q a y ta ru v c h in in g ek v iv alen t m assasi: E F cso 4 = y = 1 5 2 g / m o l 147 м Y oki u m u m iy h o ld a E = — . n M — o k sid lo vchi yoki q a y ta ru v c h in in g m o ly a r m assasi. n — o k s ilo v c h i yo k i q a y ta r u v c h in in g q a b u l q ilg a n yo k i o ‘z id a n b e rg a n e le k tro n la r so n i. M o d d a la m in g o k s ild a n ish -q a y ta rilish e k v iv alen tlari u la m in g a lm a s h in ish reak siyalarid agi e k v iv a le n tla rid a n farq qiladi. M a s a la n , y u q o rid a k e ltirilg a n re a k siy a d a o k s id lo v c h in in g e k v iv a le n t m assasi E K 2 C 12 O 7 = M / 6 = 294 / 6 = 49 g / m o l ga te n g b o 'ls a , a lm a sh in ish reak siy asid a u n in g ek viv alent m assasi: K 2 C r 2 0 7 + 2 K O H = 2 K 2 C r 0 4 + H 20 K 2 C r 2 0 7 = y = ~ = I 4 7 g / m ol b o 'la d i. B itta o k sid lo v ch i yoki q a y ta ru v c h in in g e k v iv alen ti reaksiya sh a ro iti (k o n se n tra tsiy a va h a ro r a t) va m u h itig a b o g 'liq h o ld a t u r l ic h a b o 'lis h i m u m k in . M a s a la n , k a liy p e r m a n g a n a tn in g e k v iv a le n t m assasi k islo tali m u h itd a m o ly a r m a ssa sin in g 1 /5 q ism ig a, n e y tra l sh a ro itd a 1 /3 q ism ig a, ish q o riy s h a ro itd a esa u n in g o 'z ig a te n g b o 'la d i: M n 0 4 " + 8 H + + 5e = M n 2+ + 4 H 20 Е ^ = M = = = 3 1 ,6 g / m o l M n 0 4 + 2 H 20 + З ё = M n 0 2 + 4 O H - E KMnQ4 = y = = ^ y = 5 2 ,7 g / m o l M n 0 4 + l e = M n 0 4 E KMi 1 o 4 = y = 1 5 8 g / m ol. O K SIDLA NISH-QA YTARILISH POTENSIALLARI R eak siy a u c h u n o lin g a n o k sid lo v c h i va q a y ta ru v c h i o ra s id a reak siy a k etish i yoki k etm aslig in i bilish u c h u n n o rm a l e le k tro d p o te n s ia lla rin i yoki o k sid la n is h -q a y ta rilis h p o te n s ia lla rin i b ilish k erak . U la m in g q iy m a ti 3- ja d v a ld a k eltirilg an . N o rm a l e le k tro d 148 p o te n s ia lla r i m e ta lla m in g k im y o v iy fa o llig in i x a ra k te rla y d i. P o te n sia ln in g q iy m a ti q a n c h a k ich ik b o 'ls a , m etall s h u n c h a faol b o 'lib , o s o n lik b ila n o k s id la n a d i va tu z la rid a n q iy in lik b ila n q a y ta rila d i. H a r b ir m etall n o rm a l e le k tro d p o ten sia li o 'z in ik id a n y u q o ri b o 'lg a n b o sh q a b a rc h a m e ta lla rn i u la m in g tu z la rid a n siqib c h iq a ra d i (q ay ta ra d i). G a lv a n ik e le m e n tla rd a h a m o k sid la n ish -q a y ta rilish ja ra y o n i k e tg a n lig i sa b ab li u la rn in g e le k tr y u ritu v c h i k u c h in i (E Y u K ) n o rm a l e le k tro d p o te n s ia lla rin in g fa rq id a n to p ish m u m k in . B u n d a k a tta e le k tro d p o ten sia l q iy m a tid a n , k ich ik e le k tro d p o te n sia l q iy m a ti ayriladi. M u sb a t q iy m a tli E Y uK hosil b o 'lis h i, e le k tro d p o ten sia li y u q o ri b o 'lg a n e le k tro d ok sid lo v ch i, u n d a q a y ta rilish ja ra y o n i, e le k tro d p o te n sia li quyi b o 'lg a n e le k tro d esa q a y ta ru v ch i b o 'lib , u n d a o k sid lan ish ja ra y o n i ketishin i k o 'rsa ta d i. M asalan , rux (Zn° — 2e -> Z n 2+ ) va m is (C u 2+ + 2e -» Cu°) elektrodlari uch u n norm al elektrod potensiallari qiym atini 3- jadval d an to p a m iz : E ° ( Z n 2 +/ Z n ) = —0 ,7 6 v; E ° ( C u 2 +/C u ) = 0 ,3 4 v ... M is e le k tro d in in g p o te n sia li k a tta , sh u n in g u c h u n u o k sid lo v ch i b o 'lib , u n d a q a y ta rilish ja ra y o n i b o rad i: C u 2+ + 2 e = C u° R u x e le k tr o d in in g p o te n s ia li k ic h ik , s h u n in g u c h u n u q a y ta ru v c h i b o 'lib , u n d a o k sid lan ish ja ra y o n i b o rad a: Z n ° — 2 e = Z n 2+ O k sid la n ish -q a y ta rilish rea k siy asin in g tenglam asi: C u 2++ Z n = C u + Z n 2+ G a lv a n ik e le m e n tn in g e le k tr y u ritu v c h i k u c h i (E ): E = E° ( C u 2 +/ C u ) - E° ( Z n 2 +/ Z n ) = 0 ,3 4 - ( - 0 ,7 6 ) = 1,1 v b o 'la d i. E le k tro d p o te n sia lla ri q iy m a tin i ta q q o s la b o ld in d a n o k sid l a n i s h - q a y t a r i li s h r e a k s iy a s in in g b o r is h - b o r m a s lig in i a y tis h m u m k in . M asalan, quyidagi reaksiyaning to 'g 'r i y o 'n alishda bo rish - b o rm a slig in i an iq lan g : 2 N a C l + F e 2 ( S 0 4 ) 3 = 2 F e S O , + C l 2 + N a 2 S 0 4. 1 4 9 2 C 1-+ 2 F e 3+ = 2 F e 2+ + C l 2 R e a k siy a d a x lo r io n la ri q a y ta ru v c h i 2 C l" — 2 ё = C l 2 te m ir ( I I I ) io n la ri esa o k sid lo v ch i b o 'lis h i kerak: 3+ 2+ F e + l e = F e E le k tro d p o te n sia lla ri ja d v a lid a n u la m in g s ta n d a rt elek tro d p o te n s ia lla ri q iy m a tin i to p a m iz ( 1 2 - jad v al, ilo v a d a b erilg an ). C l 2 + 2 ё = 2 C l" E° = 1,36 v Ғ е 3+ + ё = F e 2+ E° = 0 ,7 7 v O ksid lo v ch in in g e lek tro d poten siali q a y ta ru v ch in ik id a n kichik d e m a k , reaksiya t o ‘g ‘ri y o 'n a lis h d a b o rm a y d i. T eskari y o 'n a lish d a b o rish m u m k in , y a ’ni C l 2 o k sid lo v ch i, F e 2+ q a y ta ru v c h i b o 'lish i m u m k in . TAJRIBALAR Zarur asbob va reaktivlar. S h tativ (p ro b irk alari b ila n ), gorelka, n a triy n itrit, m is sim b o 'la k c h a la ri, k o n s e n trla n g a n n itra t kislota, yod k rista li, a m m o n iy d ix ro m a t tu z i, b e n z o l. E ritm alar: 0 ,2 n. n itra t k islta 2 n. su lfat k islo ta 0,0 5 n. kaliy p e rm a n g a n a t, 10 foizli n a triy g id ro k sid 0 ,5 n. n a triy n itr it, 2 n. n a triy ish q o rj, 1 n. kaliy b ro m id , 1 n. kaliy y o d id , xlorli suv. 1 - t a j r i b a . O d d iy m o d d a l a m i n g o k s id la n is h - q a y ta r ilis h reak siy alari. a ) p ro b irk a g a kaliy y o d id e ritm a s id a n 5—6 to m c h i solib, u n in g ustig a 0 ,5 ml b e n z o l q u y in g va a ra la sh tirib tu rib b ir n e c h a to m c h i xlorli suvdan tom izing. E ritm a d a yod hosil b o 'lgan ligi b e n zol q a v a tid a u n in g ran g id a n b ilin a d i. X lorli su v d a n o rtiq c h a ro q q o 's h ib e ritm a n in g ran g siz la n ish in i k u z a tin g . R a n g siz la n ish in in g sa b a b i, y o d o k sid la n ib y o d a t io n ig a ( i O J ) o 'tis h id ir. R eak siy a te n g la m a sin i y ozing va ten glash tirin g : 2K1 + C l 2 -► I 2 + 2 K C l Yechish: reaksiyaning ionli tenglamasini tuzamiz: 150 I 2 + C l 2 + H 2 0 -► H I O , + H C I KI + 3 C l 2 + 3 H 20 -> K I 0 3 + 6 H C I b) p ro b irk a g a 5 —6 to m c h i kaliy b ro m id e ritm a sid a n solib, uning ustiga 0,5 ml benzol quying. S o 'n g ra 3—4 tom chi xlorli suvdan solib yaxshilab ch ay qating . B enzol q a v a tid a to 'q sariq tusga kirgan ran g b ro m ajralganligini k o 'rsa ta d i. R eak siy a ten glam asin i yozing. 2- tajriba. M isn in g k o n s e n trla n g a n n itra t kislota ish tiro k id a o k sid lan ish i. P ro b irk ag a k ich k in a m is sim b o 'la k c h a la rin i solib, ustiga 3—4 to m c h i k o n s e n trla n g a n n itra t k islo ta d a n quying. A gar reaksiya sust k e tsa , a sta sekin q izdirin g . A jralib c h iq a y o tg an g a z n in g va eritm an in g rangiga e ’tib o r bering. R eaksiya natijasida mis (II) nitrat, a z o t (IV ) oksid va suv h osil b o 'lis h in i hisobga olib, reaksiya te n g la m a sin i tu z in g va tenglang. tajriba. K aliy p e rm a n g a n a tn in g o ksidlovchilik xossalari. U c h ta p ro b irk aga kaliy p e rm a n g a n a t eritm asid an 3—4 to m c h i soling. B irin c h i p ro b irk a g a 2— 3 to m c h i 2 n. sulfat k islo ta d a n , ik k in c h isig a s h u n c h a m iq d o rd a suv v a u c h in c h i p ro b irk a g a sh u m iq d o rd a natriy ishqoridan qo'sh in g . U ch ala probirkaga natriy sulfit k ristallarid an 1 — 2 d o n a d a n k ichik q o sh iq yo rd am id a soling va tu z e r ig u n c h a a ra la s h tir in g . P r o b ir k a la r d a g i e r itm a la r r a n g in in g o 'z g a ris h in i k u z a tin g va reaksiya te n g la m a s in i y arim rea k siy ala r usulida teng lashtiring . 1. K M n 0 4 + N a 2 S 0 3 + H 2 S 0 4 -> M n S 0 4 + N a 2 S 0 4 + H 20 2. K M n 0 4 + N a 2 S 0 3 + H 20 -> M n 0 2 + N a 2 S 0 4 + K O H 3. K M n 0 4 + N a 2 S 0 3 + N a O H -► K 2 M n 0 4 + N a 2 M n 0 4 + + N a 2 S 0 4 + H 20 ^ 4- tajriba. N itrit kisltota tuzlarining oksidlovchi va qaytaruvchilik xossalari. a ) n a triy n itritn in g o k sid lo v c h ilik xossalari. P ro b irk a g a 5—6 to m c h i kaliy y o d id , 4 —5 to m c h i 2 n. sulfat k islo ta d a n va 0,5 m l b e n zo l q u y ib a ra la sh tirin g . H osil b o 'lg a n a r a la s h m a g a n a tr iy n itr it e r i t m a s id a n 2 —4 to m c h i q o 's h ib c h a y q atin g . B en zo l q av atid a e rk in y o d ajralib chiqishin i k uzating . R eak siy a te n g la m a sin i yozing; 151 b) n a triy n itritn ig q a y ta ru v ch ilik xossasi. P ro b irk a g a 3—5 to m c h i kaliy p e rm a n g a n a t e ritm a sid a n solib, ustiga 1—2 to m c h i 2 n. sulfat kislotadan q o 'shib chayqating. S o'n g ra e ritm a ustiga ran g siz la n g u n c h a n a triy n itrit e ritm a s id a n quying. R eak siya te n g la m a sin i yozing. i / 5 - ta jr ib a . Ish q o riy m u h itd a y o d n in g d isp ro p o rsiy a la n is h reaksiyasi. Probirk aga 1—2 d o n a yod k ristallidan solib, ustiga 3—5 to m c h i 2 n. n a triy g id ro k sid e ritm a s id a n q u y in g va p ro b irk a n i isiting. E r itm a n in g ran g i q a n d a y o 'z g a r a d i. O k s id la n is h -q a y ta r ilis h reak siy asin i y o zing va tenglang: 1, + N a O H -> N a l + N a I 0 3 + H 20 S o v itilg an e ritm a g a to m c h ila tib su y u ltirilg an sulfat k islo ta d a n q o 's h in g . E ritm a rangi o 'z g a ris h ig a e ’tib o r b e rin g va reaksiy ani ten g lan g . N a l + N a I 0 3 + H 2 S 0 4 ^ I 2 + N a jS O , + H 20 6 - ta jrib a . Ichki m o lek u ly ar o k sid lan ish -q ay tarilish reaksiyasi. Q u ru q p ro b irk a g a 1—2 m ik ro s h p a te ld a a m m o n iy d ix ro m a t tu z id a n so lib , sh tativ g a qiya qilib m ah k a m la n g . R eaksiya b o s h - la n g u n c h a tu z so ling an p ro b irk a n i o stid a n q izd irin g va reaksiya b o s h la n is h i b ila n q iz d iris h n i t o 'x ta tin g . K u z a tilg a n h o d is a n i izoh lab , hosil b o 'lg an m o d d an in g rangiga e ’tib o r bering. A m m o n iy d ix ro m a t p a rc h a la n g a n d a x ro m ( I I I ) oksid, a z o t va suv hosil b o 'lis h in i hiso b g a olib reaksiya te n g la m a sin i yozing. M a s h q l a r 1. Oksidlovchi va qaytaruvchi m oddalar deb qanday moddalarga aytiladi? -j 2. Quyidagi keltirilgan jarayonlam ing qaysi biri oksidlanish va qaysi biri qaytarilish ekanligini ko'rsating. S ^ S O f S ^ -> S 2- S n ^ » S n 4+, К Д > К +, Вг 2 ^ 2 В Г 2 Н +\ и 2, H 2 % . 2 H " V 2+ %■ V O 3 , С Г -> C IO 3 , I O J % l 2, M n O ^ M n O f 3. Quyidagi reaksiyalarning qaysi biri oksidlanish-qaytarilish reak- ga kiradi? . ^ h 0 o i A ° b ( -I a) H , + Br = 2 H B r siyalariga kiradi? ^ ' oni~ 2 ■ ~ . 2 = 2 H E . ^ ^ ь ) = S iri' + * ц с № 1'яа1 ‘0 ^ d) lf t? 4 N o t = N,(5*+ 2 H , 0 k ’« ^ ‘ ctMoh. e) 2 K2C r 0 4 + H 2S 0 4 = K2C r20 7 + K 2S 0 4 + 0 H ,B O b+ 4 H F = H [B F 4] + 3 H 20 ' ^ g) Fe + S = FeS “"4. Quyidagi reaksiyalarni tenglang. S o 'n g ra ulam ing oksidlanish- qaytarilish reaksiyalarining qaysi turiga (m olekulalararo, ichki m o le kulyar, disproporsiyalanish) kirishini ko'rsating. a) K M n 0 4 + K O H -> K2MnO„ + 0 2 + H 20 b) H 2S 0 3 + H 2S S + H 20 d) N H 4N 0 2 - > N 2 + H 20 e) P + K O H + H 20 P H 3 + K H 2P 0 2 0 H 20 2 -> H 20 + 0 2 g) KMnO„ + M n S 0 4 + H 20 -► M n 0 2 + K 2S 0 4 + H 2S 0 4 *^5. E ritm a m uhitini hisobga olgan h olda oksidlanish va qaytarilish jarayonlari u ch u n yarim reaksiyalarni yozing: a) kislotali m u h itd a b) neytral m uh itd a d) ishqoriy m uhitda N 0 3 “ -> N 0 2 N 0 2 -► N 0 3 " С Ю ^ -> Cr O j - М ПО 4 -> M n 2+ М ПО 4 -> M n 0 2 Al -> A 1 0 2 N 0 3 " -> N H 3 S 0 3 2" -> S O 2" Г -> I 0 3 " l 6. Quyidagi reaksiyalarni tugallab tenglang va m olekulyar holda yozing: a) С 2О Г + 1 2 - > C 0 2 + ... b) B i 0 3 “ + C r 3+ + H + - » B i3+ + C r 2 0 2~ + d) S eO 2- + 1- + H 20 - » Se° + e) I 0 J + S 0 2 + H 20 0 М п 0 ; + Г + Н 2 0 - > g) H P 0 2" + H g 2 + + H 2 0 - > H g + ... h) P + I 0 3 “ + 0 H ~ - > 153 i) P C l 3 + C 1 0 J + H 2 0 - > . j) AsO]~ + I 2 + H 20 -> A s O f - t- ... k) Bi + Br 2 + O H _ -> B iO ^ + 1) Sb3+ + Z n + H + -> S b H 3 + ' J l . 79 g kaliy permanganat natriy oksalati bilan N a 2 C 2 0 4 kislotali sharoitda reaksiyaga kirishganda necha litr uglerodi (IV) oksid hosil bo'ladi? ( /= 27°C, p = 100 kPa. J a v o b : 6 2 ,3 /). i- 8 . Konsentrasiyasi 0,1 mol/1 bo'lgan 2 / vodorod sulfid eritmasini suyultirilgan sulfat kislota ishtirokida oksidlash uchun bir litrida 14 g kaliy dixromat erigan eritmadan qancha hajm olish kerak? ( J a v o b : 1,4 /). c, 9. 2 g magniy 0,164 g vodorodni, 17,7 g kumushni va 10,5 g misni ulam ing birikmalaridan siqib chiqaradi. Shu m etallaming ekvivalentini toping. 10. 20 ml 0,05 n temir (II) sulfatni titrlash uchun H 2 S 0 4 ishtirokida 0,02 n kaliy perm anganat eritm asidan qancha kerak? ( J a v o b : 50 ml). o 11. Quyidagi reaksiyalarga asoslanib qo'rg'oshin (IV) oksidning ekvivalentini hisoblang. a) 4 HCI + P b 0 2 -> Cl 2 + PbC l 2 + 2 H 20 b) C + P b 0 2 -> C 0 2 + Pb. <>12. Quyidagi reaksiyani tugallab oksidlovchi va qaytaruvchining ekvivalentini toping. FeSO, + KM nO, + H,SO. 4 4 2 4 L, 13. Ishqoriy sharoitda 5 ml 2 m kaliy nitratdagi N 0 3 ionini amiakka- cha qaytarish uchun qancha alyuminiy kerak bo'ladi? ( J a v o b : 0,72 g). U 14. 200 ml 0,25 n. kaliy dixromatni kislotali sharoitda qaytarish uchun qancha tem ir (II) sulfatidan kerak? ( J a v o b : 7,6 g). 15. Quyida keltirilgan reaksiva tenglamalarini elektron Ь я 1 я п я voki yarim reaksiyalar usuli bilan tenglang: if ai + 4 kcTo« ^ h 2s o 4 -Л ксТ +Iftf2 (S04)3 -hjh2o 2 .^ c f'-ttH N b 3 -> Cl2 +iNO 4 Чн'0 3 ^ K N 0 3 4fOFe ->5Fe 2 0 3 + Д + ^ 0 ( 4^A&1 3 + 4 н с ю з -> 3 HjAsb, +ИнсГ ' 5^A3P0 + 'C -> CO + A 10 -fc?P ^ ,4 4 - 2 h * л -t 6 . h 2 s o 3 + I + H 20 -> H 2 S 0 4 t? H I 154 V C 4(, -/ 7. S -Ц Cl, ^ H , 0 -> H ,S 0 4 -t{HCl 8 j L iilHN O HfeHIOj 0 NO +J?H20 93 Co -^HNfOj -^C o(N O ^ ) 2 +2ЙЬ +^Н20 -10!/Zn HTHNO, -> Й Ь 3 + 4Z n(N 0 3) 2 +?H20 ‘ 11. As -HHNO, -» H,AsO, -fcflNO, + H ,0 ^ 125zn H^KMn0 4 -tfH 2 S 0 4 -^ w fn S 0 4 + fZ n S 0 4+ K 2 S 0 4 -$ H 20 1X?A1 + K Д о , +?H 2 S 0 4 -> d 2 (S 0 4), + A1 2 (S 0 4),+ #J p + k 2 s o 4 4 ^ 2o -14.jK C 104 H?Sb -fiH 2 S 0 4 -* S 6 2 (S 0 4), +}KC1 + H20 C 15ДСГС1, + j$r 2 -ffocOH -£ K 2 d r b 4 - ^ К В г +£KC1 $ H 20 c 16. CaO Cl 2 + NaBr + H20 -> CaCl 2 + Br 2 + NaOH c 17. N a2S + N a 2 Cr 2 0 7 + H 2 S 0 4 -> Cr 2 (S 0 4), + N a 2 S 0 4 + H 20 c ( 5 ) M n S + HNO -> M n (N 0 3) 2 + S + NO + H 20 (suyul) t ( l J W s + H N O , -> M nSO. + NO + H ,0 3 4 2 c0 / M n S O 4 + P b 0 2 + H N 0 3 -> H M n 0 4+ P b S 0 4 + + P b(N O , ) 2 + H 20 / 2 p M n ( N 0 3) 2 + Pb 3 0 4 + H N O 3 -> H M n 0 4 + Pb(N O , ) 2 + + H 20 ^ (22) N a 2 S 0 3+ K 2 Cr 2 0 7 + H 2 S 0 4 -> N a 2 S 0 4 + Cr 2 (S 0 4) 3 + + K 2 S 0 4 + H 20 3 . N aA s02+ 12+ N a 2 C O ,+ H 20 -» N aH 2 A s04+ N aI + C 0 2| SnC I,+N a,W O . + HCI -> W ,Os + SnCL + NaCl + H ,0 2 2 4 2 5 4 2 SnCL + HN O.+H C1 -> SnCL + NO + H ,0 2 3 4 2 SnCl 2 + N a 0 H + B i( N 0 3) 3 -> Bi + N a 2 S n 0 3+ NaCl + + N aN O , + H 20 27) M n S 0 4 + КСЮ 3 + К О Н -> K 2 M n 0 4+KCl + H 2 0 + + K 2 S 0 4 N a C r0 2 + P b 0 2 + NaO H -> N a 2 C r 0 4 + N a 2 P b 0 2 + H 20 155 ^9T)A sH 3 + K M n 0 4 + H 2 S 0 4 H 3 As0 4 + M n S 0 4 + ^ + K ,S 0 4 + H ,0 2 4 2 N a 2 S 0 3 + Cl, + NaO H -> N a 2 S 0 4 + NaCl + H ,0 ^ f j ) N a I 0 3 + S 0 2 + H20 -> I 2 + N a 2 S 0 4 + H 2 S 0 4 t J tg A s 2 0 3 + H N 0 3 + H 20 -> H 3 A s0 4 + NO д а к ю . + N a,SO , + H ,S 0 4 -> I, + N a ,S 0 4 + K ,S 0 4 + H ,0 N . 3 2 3 2 4 2 2 4 2 4 2 LfW K M n 0 4 + C a (N 0 2) 2 + H 2 S 0 4 -> Ca ( N 0 3), + M n S 0 4 + + K 2 S 0 4 + H 20 4 Download 48 Kb. Do'stlaringiz bilan baham: |
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