Muenzaniso weMibvunzo yeKukurukurirana yeBrønsted-Lowry Acid-Base
Maacid nemabhesi ipfungwa dzakakosha mukemikari dzakagadzirwa nekunatswa nemasayendisiti mazhinji mumakore apfuura. Imwe yedzidziso dzakakurumbira idzidziso yeBrønsted-Lowry, yakakurudzirwa naJohannes Nicolaus Brønsted naThomas Martin Lowry muna 1923. Dzidziso iyi inopa maonero akafara ekuti maacid nemabhesi anoshanda sei mukuita kwemakemikari. Muchinyorwa chino, tichakurukura mienzaniso yakati wandei yematambudziko ane chekuita nepfungwa yeBrønsted-Lowry yemaacid nemabhesi uye maitiro ekuzvigadzirisa.
Pfungwa Dzekutanga dzeBrønsted-Lowry Acids neBases
Zvinoenderana nedzidziso yeBrønsted-Lowry, asidhi chinhu chinogona kupa proton (H+), nepo base chiri chinhu chinogona kugamuchira proton. Mukuita kwemakemikari, maacid nemabase zvinodyidzana kuburikidza neproton transfer process, apo imwe compound inoshanda seasidhi nekuburitsa proton, uye imwe compound inoshanda sebase nekugamuchira proton.
Mienzaniso yeAcid-Base Reactions
Muenzaniso wekuita kuri nyore pakati peasidhi nehwaro zvichienderana nedzidziso yeBrønsted-Lowry ndiko kuita kuri pakati pecopper(II) sulfate (H2SO4) nesodium hydroxide (NaOH):
\[ \text{H}_2\text{SO}_4 + \text{NaOH} \rightarrow \text{NaHSO}_4 + \text{H}_2\text{O} \]
Mukuita uku, sulfuric acid (H2SO4) inoshanda seBrønsted-Lowry acid nekuti inopa proton (H+) kuNaOH, iyo inogamuchira proton.
Mibvunzo yemuenzaniso nehurukuro
Mubvunzo 1: Kuziva maAcids neMabhesi
Mubvunzo:
Ziva maBrønsted-Lowry acids nemabhesi mukuita kunotevera:
\[ \text{NH}_3 + \text{H}_2\text{O} \rightarrow \text{NH}_4^+ + \text{OH}^- \]
Kukurukurirana:
Mukuita uku, ammonia (NH3) nemvura (H2O) ndizvo zvinogadzirisa zvinhu, nepo ammonium ions (NH4+) uye hydroxide ions (OH-) zviri zvinhu zvinogadzira zvinhu. Ngationei kuti ndeipi inoshanda seasidhi uye ndeipi inoshanda sehwaro.
– NH3 inoshanda sehwaro nekuti inogamuchira mapurotoni (H+) kubva kuH2O kuti iumbe NH4+.
– H2O inoshanda seasidhi nekuti inopa proton (H+) kuNH3 kuti igadzire OH-.
Saka, mumhinduro iyi:
- NH3 inzvimbo yeBrønsted-Lowry.
– H2O iBrønsted-Lowry acid.
Mubvunzo 2: Kunyora Maitiro ekubatanidza
Mubvunzo:
Nyora ma conjugate acid-base pairs emhinduro dzinotevera:
\[ \text{HCl} + \text{H}_2\text{O} \rightarrow \text{H}_3\text{O}^+ + \text{Cl}^- \]
Kukurukurirana:
Mukuita uku, HCl inoshanda seBrønsted-Lowry acid nekupa proton (H+) kuH2O. Mvura (H2O) inogamuchira proton uye inoshanda seBrønsted-Lowry base. Mushure mekurasikirwa neproton, HCl inoshanduka kuita Cl-, uye H2O, mushure mekuwana proton, inoshanduka kuita H3O+.
– Asidhi (HCl) nehwaro hwayo hwe conjugate (Cl-)
– H2O (H2O) uye conjugate acid yayo (H3O+)
Saka, conjugate acid-base pair mukuita uku ndeiyi:
– HCl / Cl-
– H2O / H3O+
Mubvunzo 3: Kuverenga pH yeWeak Acid Solution
Mubvunzo:
Verenga pH ye 0.1 M solution ye acetic acid (CH3COOH) kana zvichizivikanwa kuti acid dissociation constant (Ka) iri \(1.8 \times 10^{-5}\).
Kukurukurirana:
Acetic acid iasidhi isina simba, uye mumvura inongoerekana yaita ioni zvishoma zvichienderana ne equation inotevera:
\[ \text{CH}_3\text{COOH} \rightleftharpoons \text{CH}_3\text{COO}^- + \text{H}^+ \]
Matanho ekuverenga pH ndeaya anotevera:
1. Gadzirai nzira yekuenzanisa uchishandisa chiyero chekutanga uye shanduko yechiyero:
\[ \text{Ka} = \frac{[\text{CH}_3\text{COO}^-][\text{H}^+]}{[\text{CH}_3\text{COOH}]} \]
2. Tsiva tsika dzinozivikanwa wobva wagadzirisa \([H^+]\):
\[ 1.8 \kawa 10^{-5} = \frac{x^2}{0.1 – x} \]
Sezvo \(x\) iri diki zvikuru kana tichienzanisa ne0.1, tinogona kufungidzira \(0.1 - x \approx 0.1\):
\[ 1.8 \kawa 10^{-5} = \frac{x^2}{0.1} \]
\[ x^2 = 1.8 \kawa 10^{-6} \]
\[ x = \sqrt{1.8 \kawa 10^{-6}} \]
\[ x \inenge 1.34 \kawa 10^{-3} \]
3. Verenga pH:
\[ \text{pH} = -\log[\text{H}^+] \]
\[ \text{pH} = -\log(1.34 \times 10^{-3}) \]
\[ \text{pH} \inenge 2.87 \]
Saka, pH ye 0.1 M acetic acid solution inenge 2.87.
Mubvunzo 4: Kuziva Mhinduro dzeAmphiprotic
Mubvunzo:
Tsvaga mhinduro ye amphiprotic mumhinduro inotevera uye tsanangura chikonzero nei:
\[ \text{HCO}_3^- + \text{H}_2\text{O} \rightleftharpoons \text{H}_2\text{CO}_3 + \text{OH}^- \]
Kukurukurirana:
Mhinduro ye amphiprotic imhinduro inogona kushanda seasidhi kana kuti base, zvichienderana nemamiriro ekuita. Mumuenzaniso wekuita uri pamusoro apa:
– \(\text{HCO}_3^-\) inoshanda sehwaro kana ikagamuchira proton kubva ku \(\text{H}_2\text{O}\), ichiburitsa \(\text{H}_2\text{CO}_3\).
– \(\text{HCO}_3^-\) inogonawo kushanda seasidhi pasi pemamwe mamiriro ezvinhu, ichiburitsa proton uye ichigadzira \(\text{CO}_3^{2-}\).
Izvi zvinoratidza kuti ion \(\text{HCO}_3^-\) ine amphiprotic. Inogona kushanda se acid (proton donor) uye se base (proton acceptor), zvichienderana nechimwe chinhu chainopindura nacho.
Nemibvunzo iyi yemuenzaniso, tinogona kunzwisisa zviri nani kuti dzidziso yeBrønsted-Lowry acid-base inoshandiswa sei kuongorora nekufanotaura kudyidzana kwemakemikari. Kunzwisisa kwakasimba kwedzidziso iyi ndiyo hwaro hwekushandiswa kwakawanda mukemistri, biochemistry, nedzimwe sainzi.
