Mienzaniso yeMibvunzo Inokurukura Mhinduro dzeBuffer
Mhinduro ye "buffer", inowanzonzi "buffer", imhinduro inochengetedza pH yayo kunyangwe kana huwandu hushoma hweasidhi yakasimba kana base hwakawedzerwa. Kugona uku kunoita kuti mhinduro dze "buffer" dzive dzakakosha mukushandiswa kwakasiyana-siyana kwemakemikari, zvipenyu, uye kunyange mumaindasitiri. Muchinyorwa chino, tichaongorora mimwe mienzaniso uye tichakurukura mhinduro dze "buffer".
Kunzwisisa Mhinduro dzeBuffer
Mhinduro dzeBuffer dzinowanzo kuve nemusanganiswa weasidhi isina simba nechigadziko chayo che conjugate kana chigadziko chisina simba neasidhi yayo ye conjugate. Kana acid kana chigadziko chikawedzerwa kune idzi mhinduro, mhinduro inobuda inobatsira kuchengetedza pH yemhinduro mukati mehuwandu hwakatarwa. Muchirevo ichi, pH chiyero cheacidity kana alkalinity yemhinduro.
Basa uye Kukosha kweBuffer Solutions
Mhinduro dzeBuffer dzine basa rakakosha muminda yakasiyana-siyana:
1. Biochemistry: Maitiro akawanda e enzymes uye physiological anoitika pa pH chaiyo, saka mhinduro dze buffer dzinobatsira mukuchengetedza mamiriro akanaka.
2. Maindasitiri: Mumaindasitiri ezvekudya nemishonga, kudzora pH kwakakodzera kwakakosha pamhando yezvigadzirwa uye kuchengetedzeka kwazvo.
3. Kuedza kweMakemikoro: Murabhoritari, mhinduro dzebuffer dzinoshandiswa kudzora pH panguva yekuchinja kwemakemikari.
Mashandiro Ekugadzirisa Matambudziko
Mhinduro dzeBuffer dzinoshanda pahwaro hwekuenzana. Pamhinduro ine asidi isina simba \(HA \) nemunyu wayo we conjugate base \(A^- \), kuwedzerwa kweasidhi shoma kana base kuchaita kuti pave nekuchinja kukuru muhuwandu hwemaion \(H^+ \) mazinga.
Mibvunzo yemuenzaniso nekukurukurirana
Kuti tinzwisise zvakawanda, ngationgororei mimwe mibvunzo nehurukuro dzine chekuita nemhinduro dzebuffer.
Mubvunzo 1: Kuverenga pH yeAcid Buffer Solution
Mubvunzo:
Mhinduro yebuffer inogadzirwa nekusanganisa 0,1 mol yeacetic acid (CH₃COOH) ne0,1 mol yesodium acetate (CH₃COONa) mu 1 litre yemhinduro. Iyo dissociation constant yeacetic acid (\( K_a \)) ndeye \( 1,8 \times 10^{-5} \). Verenga pH yemhinduro.
Kukurukurirana:
Mhinduro iyi yebuffer ine weak acid (CH₃COOH) uye conjugate base yayo (CH₃COO⁻). Tinogona kushandisa Henderson-Hasselbalch equation kuverenga pH yebuffer solution:
\[ \text{pH} = \text{p}K_a + \log \left( \frac{[A^-]}{[HA]} \right) \]
Dimana:
\[ \text{p}K_a = -\log (K_a) \]
\[ \text{p}K_a = -\log (1,8 \kawa 10^{-5}) \]
\[ \text{p}K_a \inenge 4,74 \]
Sezvo kuwanda kwe \( [A^-] \) uye \( [HA] \) kwakafanana (0,1 M):
\[ \text{pH} = 4,74 + \log \left( \frac{[0,1]}{[0,1]} \right) \]
\[ \mashoko{pH} = 4,74 + \log(1) \]
\[ \mashoko{pH} = 4,74 \]
Saka, pH yemushonga webuffer i4,74.
Mubvunzo 2: Kuwedzera Acid kuBuffer Solution
Mubvunzo:
Chii chinochinja pH kana 0,01 mol yeHCl ikawedzerwa mu 1 litre ye buffer solution kubva kuMubvunzo 1?
Kukurukurirana:
Kuwedzerwa kweHCl kuchawedzera huwandu hwe \( H^+ \) mumushonga. Mhinduro inoitika ndeiyi:
\[ \text{H}^+ + \text{CH}_3\text{COO}^- \rightarrow \text{CH}_3\text{COOH} \]
Tinofanira kuverenga kuti mamoles mangani e \( H^+ \) uye kuti anokanganisa sei kuwanda kwe \( \text{CH}_3\text{COOH} \) uye \( \text{CH}_3\text{COO}^- \).
Pakutanga:
\[ [\text{CH}_3\text{COO}^-] = 0,1 \, \text{mol} \]
\[ [\text{CH}_3\text{COOH}] = 0,1 \, \text{mol} \]
Mushure mekuwedzera 0,01 mol yeHCl:
\[ [\text{CH}_3\text{COO}^-] = 0,1 – 0,01 = 0,09 \, \text{mol} \]
\[ [\text{CH}_3\text{COOH}] = 0,1 + 0,01 = 0,11 \, \text{mol} \]
Shandisa equation yaHenderson-Hasselbalch kuverenga pH itsva:
\[ \text{pH} = \text{p}K_a + \log \left( \frac{[A^-]}{[HA]} \right) \]
\[ \text{pH} = 4,74 + \log \left( \frac{0,09}{0,11} \right) \]
\[ \mashoko{pH} = 4,74 + \log(0,818) \]
\[ \mashoko{pH} = 4,74 + (-0,088) \]
\[ \mashoko{pH} = 4,65 \]
Saka, pH yemushonga webuffer mushure mekuwedzera HCl inoshanduka kubva pa4,74 kusvika pa4,65.
Mubvunzo 3: Kuwedzera Base kuBuffer Solution
Mubvunzo:
Chii chinochinja pH kana 0,01 mol yeNaOH ikawedzerwa mu 1 litre ye buffer solution kubva kuMubvunzo 1?
Kukurukurirana:
Kuwedzerwa kweNaOH kunoderedza kuwanda kweH⁺ mumushonga neOH⁻ kubva kuNaOH. Maitiro anoitika:
\[ \text{OH}^- + \text{CH}_3\text{COOH} \rightarrow \text{CH}_3\text{COO}^- + \text{H}_2\text{O} \]
Pakutanga:
\[ [\text{CH}_3\text{COOH}] = 0,1 \, \text{mol} \]
\[ [\text{CH}_3\text{COO}^-] = 0,1 \, \text{mol} \]
Mushure mekuwedzera 0,01 mol yeNaOH:
\[ [\text{CH}_3\text{COOH}] = 0,1 – 0,01 = 0,09 \, \text{mol} \]
\[ [\text{CH}_3\text{COO}^-] = 0,1 + 0,01 = 0,11 \, \text{mol} \]
Shandisa equation yaHenderson-Hasselbalch kuverenga pH itsva:
\[ \text{pH} = \text{p}K_a + \log \left( \frac{[A^-]}{[HA]} \right) \]
\[ \text{pH} = 4,74 + \log \left( \frac{0,11}{0,09} \right) \]
\[ \mashoko{pH} = 4,74 + \log(1,222) \]
\[ \mashoko{pH} = 4,74 + 0,087 \]
\[ \mashoko{pH} = 4,83 \]
Saka, pH yemushonga webuffer mushure mekuwedzera NaOH inoshanduka kubva pa4,74 kusvika pa4,83.
Mubvunzo 4: Kuona Kuumbwa kweBuffer nePh yakati
Mubvunzo:
Kuti mugadzire 1 litre yemusanganiswa webuffer ine pH 5,0 muchishandisa acetic acid (CH₃COOH) uye sodium acetate (CH₃COONa), mangani mamoles echikamu chimwe nechimwe anodiwa? \( K_a \) yeacetic acid i \( 1,8 \times 10^{-5} \).
Kukurukurirana:
Shandisa equation yaHenderson-Hasselbalch:
\[ \text{pH} = \text{p}K_a + \log \left( \frac{[A^-]}{[HA]} \right) \]
Kutanga, verenga pKₐ:
\[ \text{p}K_a = -\log (1,8 \kawa 10^{-5}) \]
\[ \text{p}K_a \inenge 4,74 \]
Wobva waisa pH yaunoda:
\[ 5,0 = 4,74 + \log \left( \frac{[A^-]}{[HA]} \right) \]
\[ 0,26 = \log \left( \frac{[A^-]}{[HA]} \right) \]
Kushandisa hunhu hwema logarithms:
\[ \frac{[A^-]}{[HA]} = 10^{0,26} \]
\[ \frac{[A^-]}{[HA]} \inenge 1,82 \]
Izvi zvinoreva kuti pamore imwe chete yeCH₃COOH, mamore 1,82 eCH₃COONa anodiwa. Pachiyero ichi mu1 litre:
Semuenzaniso, ngatitii CH₃COOH = x mol, saka CH₃COONa = 1,82x mol. Huwandu hwese i (x + 1.82x) = 2,82x mol, sezvo tiri kugadzira 1 litre yebuffer, saka:
\[x + 1.82x = 1 \]
\[ 2.82x = 1 \]
\[ x = \frac{1}{2.82} \inenge 0.355 \]
Saka, musanganiswa unodiwa:
– CH₃COOH: 0,355 mol
– CH₃COONA: 1,82 0,355 ≈ 0,646 mol
Saka tinoda 0,355 mol yeacetic acid uye 0,646 mol yesodium acetate kuti tigadzire 1 litre yebuffer solution ine pH 5,0.
Chinyorwa chino chinopa mienzaniso yakasiyana-siyana yezvinetso zvine chekuita nemhinduro dzekugadzirisa matambudziko pamwe nehurukuro dzadzo kuti tinzwisise zvakadzama pfungwa iyi. Tinovimba kuti ruzivo urwu runobatsira pakunzwisisa mashandiro anoita mhinduro dzekugadzirisa matambudziko pamwe nekushandiswa kwadzo mumamiriro akasiyana-siyana.
