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Kimyo

Course: Kimyo > Unit 13

Lesson 2: Kislota-asos muvozanati

Kk va Ka orasidagi bogʻliqlik

Kuchsiz kislota Kk qiymati va uning tutash asosi Ka qiymati orasidagi bogʻliqlik. Kk va Ka hamda pKk va pKb larni almashtirishga oid tenglamalar.

Asosiy tushunchalar

Tutash asos-kislota juftlarida kislotaning dissotsilanish doimiysi K, start subscript, start text, k, end text, end subscriptva asosning ionlanish doimiysi K, start subscript, start text, a, end text, end subscript oʻzaro quyidagicha bogʻlangan:

K, start subscript, start text, k, end text, end subscript, dot, K, start subscript, start text, a, end text, end subscript, equals, K, start subscript, start text, s, end text, end subscript
bu yerda K, start subscript, start text, s, end text, end subscript avtoionlanish doimiysi

start text, p, end text, K, start subscript, start text, k, end text, end subscript, plus, start text, p, end text, K, start subscript, start text, a, end text, end subscript, equals, 14, space, space, 25, degrees, start text, C, end text, start text, space, d, a, space, end text

Kirish: kuchsiz kislota va asoslarning ionlanishi qaytar jarayondir

Kuchsiz kislotalarni umumiy start color #1fab54, start text, H, K, end text, end color #1fab54 deb yozsak, ular suvga start text, H, end text, start superscript, plus, end superscript (proton) berib tutash asos - start color #1fab54, start text, K, end text, start superscript, minus, end superscript, end color #1fab54 va start text, H, end text, start subscript, 3, end subscript, start text, O, end text, start superscript, plus, end superscript hosil qiladi:

[Kuchli va kuchsiz kislotalar orasidagi farqni tushunmadim!]

start text, H, K, end text, left parenthesis, s, point, e, point, right parenthesis, plus, start text, H, end text, start subscript, 2, end subscript, start text, O, end text, left parenthesis, s, right parenthesis, \rightleftharpoons, start text, H, end text, start subscript, 3, end subscript, start text, O, end text, start superscript, plus, end superscript, left parenthesis, s, point, e, point, right parenthesis, plus, start text, K, end text, start superscript, minus, end superscript, left parenthesis, s, point, e, point, right parenthesis

space, space, start color #1fab54, start text, k, i, s, l, o, t, a, end text, end color #1fab54, space, space, space, space, space, space, space, space, space, space, start text, a, s, o, s, end text, space, space, space, space, space, space, space, space, space, space, space, space, start text, k, i, s, l, o, t, a, end text, space, space, space, space, space, space, space, space, space, space, space, space, space, space, start color #1fab54, start text, a, s, o, s, end text, end color #1fab54

Kuchsiz asos (start color #aa87ff, start text, A, end text, end color #aa87ff) ham kuchsiz kislotalarga oʻxshab suvdan proton qabul qilib tutash kislota – start color #aa87ff, start text, H, A, end text, start superscript, plus, end superscript, end color #aa87ff va start text, O, H, end text, start superscript, minus, end superscript ni hosil qiladi:

start text, A, end text, left parenthesis, s, point, e, point, right parenthesis, plus, start text, H, end text, start subscript, 2, end subscript, start text, O, end text, left parenthesis, s, right parenthesis, \rightleftharpoons, start text, H, A, end text, start superscript, plus, end superscript, left parenthesis, s, point, e, point, right parenthesis, plus, start text, O, H, end text, start superscript, minus, end superscript, left parenthesis, s, point, e, point, right parenthesis

space, space, start color #aa87ff, start text, a, s, o, s, end text, end color #aa87ff, space, space, space, space, space, space, space, space, space, start text, k, i, s, l, o, t, a, end text, space, space, space, space, space, space, space, space, space, space, start color #aa87ff, start text, k, i, s, l, o, t, a, end text, end color #aa87ff, space, space, space, space, space, space, space, space, space, space, start text, a, s, o, s, end text

Kuchsiz kislota va asoslarning ionlanish reaksiyasi muvozanat doimiysi har bir modda uchun alohida aniqlanadi. Ushbu mavzuda tutash kislota-asos juftlarining muvozanat doimiylari K, start subscript, start text, k, end text, end subscript va K, start subscript, start text, a, end text, end subscript lar orasidagi bogʻliqlikni oʻrganamiz.

Izoh: ushbu mavzuda barcha eritmalar suvli eritmalar deb hisoblansin.

start text, H, K, end text kislota uchun K, start subscript, start text, k, end text, end subscript ni topish

Bir negizli kuchsiz kislota (start text, H, K, end text) uchun dissotsilanish reaksiyasini quyidagicha yozish mumkin:

Ushbu reaksiya mahsulotlari start text, H, K, end text ning tutash asosi boʻlgan start text, K, end text, start superscript, minus, end superscript va start text, H, end text, start subscript, 3, end subscript, start text, O, end text, start superscript, plus, end superscript. Ushbu reaksiyaning muvozanat doimiysi (K, start subscript, start text, k, end text, end subscript) uchun quyidagi ifodani yozish mumkin:

K, start subscript, start text, k, end text, end subscript, equals, start fraction, open bracket, start text, H, end text, start subscript, 3, end subscript, start text, O, end text, start superscript, plus, end superscript, close bracket, open bracket, start text, K, end text, start superscript, minus, end superscript, close bracket, divided by, open bracket, start text, H, K, end text, close bracket, end fraction

[Suv-chi?]

Asos xossali start text, K, end text, start superscript, minus, end superscript uchun K, start subscript, start text, a, end text, end subscript topish

start text, K, end text, start superscript, minus, end superscript asos xossasini namoyon qilgani sababli start text, K, end text, start superscript, minus, end superscript uchun qaytar reaksiya yozish mumkin, yaʼni bunda start text, K, end text, start superscript, minus, end superscript suvdan proton qabul qiladi:

start text, K, end text, start superscript, minus, end superscript, left parenthesis, s, point, e, point, right parenthesis, plus, start text, H, end text, start subscript, 2, end subscript, start text, O, end text, left parenthesis, s, right parenthesis, \rightleftharpoons, start text, H, K, end text, left parenthesis, s, point, e, point, right parenthesis, plus, start text, O, H, end text, start superscript, minus, end superscript, left parenthesis, s, point, e, point, right parenthesis

Ushbu reaksiya mahsulotlari start text, H, K, end text va start text, O, H, end text, start superscript, minus, end superscript. Bu reaksiya uchun muvozanat doimiysi (K, start subscript, start text, a, end text, end subscript)ni topishimiz mumkin:

K, start subscript, start text, a, end text, end subscript, equals, start fraction, open bracket, start text, H, K, end text, close bracket, open bracket, start text, O, H, end text, start superscript, minus, end superscript, close bracket, divided by, open bracket, start text, K, end text, start superscript, minus, end superscript, close bracket, end fraction

Ushbu reaksiya start text, H, K, end text ning suv bilan reaksiyasiga oʻxshasa-da, bu ikki reaksiya bir-biridan katta farq qiladi. start text, H, K, end text suv bilan kislota sifatida reaksiyaga kirishganda reaksiya mahsulotlaridan biri start text, H, end text, start subscript, 3, end subscript, start text, O, end text, start superscript, plus, end superscript boʻlsa, uning tutash asosi - start text, K, end text, start superscript, minus, end superscript asos sifatida suv bilan reaksiyaga kirishganda mahsulotlardan biri sifatida start text, O, H, end text, start superscript, minus, end superscripthosil boʻladi.

Tutash kislota-asos juftlari uchun K, start subscript, start text, k, end text, end subscript va K, start subscript, start text, a, end text, end subscript lar orasidagi bogʻliqlik

start text, H, K, end text ga tegishli K, start subscript, start text, k, end text, end subscript ni va start text, K, end text, start superscript, minus, end superscript ga tegishli K, start subscript, start text, a, end text, end subscript ni oʻzaro koʻpaytirsak, quyidagini olamiz:

\begin{aligned}K_\text{k}\cdot K_\text{a}&=\Bigg(\dfrac{[\text{H}_3\text{O}^+]\cancel{[\text{K}^-]}}{\cancel{[\text{HK}]}}\Bigg)\Bigg(\dfrac{\cancel{[\text{HK}]}[\text{OH}^-]}{\cancel{[\text{K}^-]}}\Bigg)\\ \\ &=[\text{H}_3\text{O}^+][\text{OH}^-]\\ \\ &=K_\text{s}\end{aligned}

[Ks nima?]

bu yerda K, start subscript, start text, s, end text, end subscript suvning dissotsilanish doimiysi. Tutash kislota-asoslarning K, start subscript, start text, k, end text, end subscript va K, start subscript, start text, a, end text, end subscript lari orasidagi bogʻliqlik juda muhim ahamiyatga ega. Shuningdek, yana bir ajoyib tenglama olish uchun K, start subscript, start text, s, end text, end subscript ning 25, degrees, start text, C, end text dagi qiymatidan foydalanishimiz mumkin:

\begin{aligned}K_\text{k}\cdot K_\text{a}&=K_\text{s}\\ \\ &=1{,}0\times 10^{-14}~\text{ }25\,^\circ \text C\quad\quad\quad\quad(\text{1-teng.})\end{aligned}

1-teng. ning har ikkala tomonidan manfiy log, start base, 10, end base olsak, quyidagi tenglama hosil boʻladi:

start text, p, end text, K, start subscript, start text, k, end text, end subscript, plus, start text, p, end text, K, start subscript, start text, a, end text, end subscript, equals, 14, space, space, start text, space, end text, 25, degrees, start text, C, end text, left parenthesis, start text, 2, negative, t, e, n, g, point, end text, right parenthesis

Ushbu tenglamadan foydalanib tutash kislotaning K, start subscript, start text, k, end text, end subscript qiymati maʼlum boʻlganda kuchsiz asosning K, start subscript, start text, a, end text, end subscript (yoki start text, p, end text, K, start subscript, start text, a, end text, end subscript) qiymatini topishimiz mumkin. Shuningdek, tutash asosning K, start subscript, start text, a, end text, end subscript qiymati maʼlum boʻlganda kuchsiz kislotaning K, start subscript, start text, k, end text, end subscript (yoki start text, p, end text, K, start subscript, start text, k, end text, end subscript) qiymatini ham topishimiz mumkin.

Bu tenglama faqatgina tutash kislota-asos juftlarida ishlashini eslab qolish zarur!! Tutash kislota-asos juftlarini qanday aniqlashni eslab olish uchun tutash kislota-asos juftlari mavzusini koʻring.

Nazorat savoli: 25, degrees, start text, C, end text dagi K, start subscript, start text, a, end text, end subscript (start text, N, H, end text, start subscript, 3, end subscript) qiymatini bilgan holda quyidagilardan qaysi birini aniqlash mumkin?

(Tanlov A)
K, start subscript, start text, k, end text, end subscript (start text, N, H, end text, start subscript, 3, end subscript )
(Tanlov B)
K, start subscript, start text, a, end text, end subscript (start text, N, H, end text, start subscript, 2, end subscript, start superscript, minus, end superscript)
(Tanlov D)
K, start subscript, start text, k, end text, end subscript (start text, N, H, end text, start subscript, 4, end subscript, start superscript, plus, end superscript)
(Tanlov E)
Yuqoridagilardan hech biri

[Javobni koʻrish]

Misol: kuchsiz asos uchun K, start subscript, start text, a, end text, end subscript ni topish

Ftorid kislota left parenthesis, start text, H, F, end text, right parenthesis ning start text, p, end text, K, start subscript, start text, k, end text, end subscript qiymati 25, degrees, start text, C, end text da 3, comma, 36 ga teng.

start text, F, end text, start superscript, minus, end superscript, left parenthesis, s, point, e, point, right parenthesis uchun K, start subscript, start text, a, end text, end subscript ni toping

Keling, ushbu masalani bosqichma-bosqich ishlaymiz.

1-qadam. Tutash kislota-asos jufti borligiga ishonch hosil qilib olamiz

Tutash kislota-asos juftlari orasidagi bogʻliqlikni start text, H, F, end text ning dissotsilanish reaksiyasini yozib aniqlashimiz mumkin:

start text, H, F, end text, left parenthesis, s, point, e, point, right parenthesis, plus, start text, H, end text, start subscript, 2, end subscript, start text, O, end text, left parenthesis, s, right parenthesis, \rightleftharpoons, start text, F, end text, start superscript, minus, end superscript, left parenthesis, s, point, e, point, right parenthesis, plus, start text, H, end text, start subscript, 3, end subscript, start text, O, end text, start superscript, plus, end superscript, left parenthesis, s, point, e, point, right parenthesis

Koʻrib turibmizki, start text, H, F, end text suvga proton berib start text, H, end text, start subscript, 3, end subscript, start text, O, end text, start superscript, plus, end superscript va start text, F, end text, start superscript, minus, end superscript hosil qilayapti. Demak, start text, H, F, end text ning tutash asosi start text, F, end text, start superscript, minus, end superscript ekan. Bundan xulosa qilish mumkinki, start text, H, F, end text ning start text, p, end text, K, start subscript, start text, k, end text, end subscript sidan start text, F, end text, start superscript, minus, end superscript ning start text, p, end text, K, start subscript, start text, a, end text, end subscript sini aniqlashda foydalanish mumkin. Ura!

2-qadam. start text, p, end text, K, start subscript, start text, k, end text, end subscript dan start text, p, end text, K, start subscript, start text, a, end text, end subscript ni topishda 2-teng. dan foydalanish

2-teng. ni qayta yozib start text, p, end text, K, start subscript, start text, a, end text, end subscript ni topsak quyidagi ifoda hosil boʻladi:

start text, p, end text, K, start subscript, start text, a, end text, end subscript, equals, 14, comma, 00, minus, start text, p, end text, K, start subscript, start text, k, end text, end subscript

start text, p, end text, K, start subscript, start text, k, end text, end subscript ning qiymatini tenglamaga qoʻysak, quyidagi natijani olamiz:

start text, p, end text, K, start subscript, start text, a, end text, end subscript, equals, 14, comma, 00, minus, left parenthesis, 3, comma, 36, right parenthesis, equals, 10, comma, 64

Demak, start text, p, end text, K, start subscript, start text, a, end text, end subscript 10, comma, 64 ga teng.

3-qadam. start text, p, end text, K, start subscript, start text, a, end text, end subscript dan foydalanib K, start subscript, start text, a, end text, end subscript ni hisoblash

Quyidagi ifodadan foydalanib start text, p, end text, K, start subscript, start text, a, end text, end subscript dan K, start subscript, start text, a, end text, end subscript ni topishimiz mumkin:

start text, p, end text, K, start subscript, start text, a, end text, end subscript, equals, minus, log, left parenthesis, K, start subscript, start text, a, end text, end subscript, right parenthesis

Tenglamadan K, start subscript, start text, a, end text, end subscript ni topsak, quyidagi ifoda hosil boʻladi:

K, start subscript, start text, a, end text, end subscript, equals, 10, start superscript, minus, start text, p, end text, K, start subscript, start text, a, end text, end subscript, end superscript

start text, p, end text, K, start subscript, start text, a, end text, end subscript qiymatini oʻrniga qoʻyib hisoblaymiz va quyidagi natijani olamiz:

K, start subscript, start text, a, end text, end subscript, equals, 10, start superscript, minus, left parenthesis, 10, comma, 64, right parenthesis, end superscript, equals, 2, comma, 3, times, 10, start superscript, minus, 11, end superscript

Demak, start text, F, end text, start superscript, minus, end superscript uchun K, start subscript, start text, a, end text, end subscript qiymati 2, comma, 3, times, 10, start superscript, minus, 11, end superscript ga teng.

Xulosa

Tutash kislota-asos juftlarining K, start subscript, start text, k, end text, end subscript va K, start subscript, start text, a, end text, end subscript lari orasida quyidagicha bogʻliqlik bor:

K, start subscript, start text, s, end text, end subscript, equals, K, start subscript, start text, k, end text, end subscript, dot, K, start subscript, start text, a, end text, end subscript

start text, p, end text, K, start subscript, start text, k, end text, end subscript, plus, start text, p, end text, K, start subscript, start text, a, end text, end subscript, equals, 14, space, space, 25, degrees, start text, C, end text, start text, space, d, a, space, end text

[Qoʻshimcha maʼlumot va manbalar]

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Kirish

Saralash:

Hozircha izohlar yoʻq.

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Kimyo

Course: Kimyo > Unit 13

Asosiy tushunchalar

Kirish: kuchsiz kislota va asoslarning ionlanishi qaytar jarayondir

HK\text{HK}HKstart text, H, K, end text kislota uchun KkK_\text{k}Kk​K, start subscript, start text, k, end text, end subscript ni topish

Asos xossali K−\text{K}^-K−start text, K, end text, start superscript, minus, end superscript uchun KaK_\text{a}Ka​K, start subscript, start text, a, end text, end subscript topish

Tutash kislota-asos juftlari uchun KkK_\text{k}Kk​K, start subscript, start text, k, end text, end subscript va KaK_\text{a}Ka​K, start subscript, start text, a, end text, end subscript lar orasidagi bogʻliqlik

Misol: kuchsiz asos uchun KaK_\text{a}Ka​K, start subscript, start text, a, end text, end subscript ni topish