Mienzaniso yeMibvunzo Inokurukura Hunhu neMafungiro eAcids neBases
Hunhu nepfungwa dzemaasidhi nemabhesi inyaya dzakakosha mukemistri, nekushandiswa kwakapararira muminda yakasiyana-siyana, kusanganisira indasitiri, pharmacy, uye biochemistry. Kunzwisisa pfungwa huru nekushandiswa kwehunhu hweasidhi-base kwakakosha kuvadzidzi nevatsvagurudzi. Chinyorwa chino chichakurukura mienzaniso yakati wandei yezvinetso zvine chekuita nehunhu nepfungwa dzemaasidhi nemabhesi, pamwe chete nemhinduro dzazvo, kuti vaverengi vawane mufananidzo wakajeka.
Pfungwa Dzekutanga dzeAcids neBases
Tisati taongorora mibvunzo nehurukuro dzayo, ngationgororei dzimwe pfungwa huru pamusoro peasidhi nemabhesi.
Zvakaoma:
– Asidhi zvinhu zvinogona kupa mahydrogen ions (H⁺) mumushonga.
– Asidhi ane zvinhu zvinoita kuti munhu ave neacidic, semuenzaniso kuravira kunovava (sevhiniga) uye kugona kuita zvinoenderana nesimbi.
Bass:
– Hwaro chinhu chinogona kugamuchira ma hydrogen ions kana kuita ma hydroxide ions (OH⁻) mumushonga.
- Mabhesi ane zvinhu zvakakosha, zvakaita sekunaka kunovava uye kutsvedza (senge sipo).
Dzidziso yeAcid-Base:
– Dzidziso yeArrhenius: Asidhi anogadzira H⁺ uye mabhesi anogadzira OH⁻ mumvura ine mvura.
– Dzidziso yaBrønsted-Lowry: Asidhi iH⁺ donor uye mabhesi iH⁺ acceptors.
– Dzidziso yaLewis: Asidhi inogamuchira maerekitironi maviri uye mabhesi ivapi vemaerekitironi maviri.
Mibvunzo yemuenzaniso nehurukuro
Muenzaniso Mubvunzo 1: Kuverenga pH yeSolution yeAcid Yakasimba
Mubvunzo:
Verenga pH ye 0,01 M HCl solution.
Kukurukurirana:
HCl iasidhi yakasimba iyo inozopatsanurwa zvachose mumushonga kuti ibudise H⁺ neCl⁻. Kuwanda kweH⁺ kwakafanana nekuwanda kwekutanga kweHCl.
\[ [H⁺] = 0,01 \, M \]
pH inotsanangurwa se negative base 10 logarithm yehuwandu hwehydrogen ion:
\[ \text{pH} = -\log[H⁺] \]
\[ \mashoko{pH} = -\log(0,01) \]
\[ \mashoko{pH} = 2 \]
Saka, pH ye 0,01 M HCl solution i2.
Muenzaniso Mubvunzo 2: Kuverenga pH yeSolution Yakasimba Yebase
Mubvunzo:
Verenga pH ye 0,001 M NaOH solution.
Kukurukurirana:
NaOH ihwaro hwakasimba huchapatsanurwa zvachose mumushonga, zvichiburitsa Na⁺ neOH⁻. Kuwanda kweOH⁻ kwakafanana nekuwanda kwekutanga kweNaOH.
\[ [OH⁻] = 0,001 \, M \]
PoH inotsanangurwa se negative base 10 logarithm ye hydroxide ion concentration:
\[ \text{pOH} = -\log[OH⁻] \]
\[ \text{pOH} = -\log(0,001) \]
\[ \mashoko{pOH} = 3 \]
pH ne pOH zvakabatana ne equation:
\[ \text{pH} + \text{pOH} = 14 \]
\[ \mashoko{pH} = 14 – 3 \]
\[ \mashoko{pH} = 11 \]
Saka, pH ye 0,001 M NaOH solution i11.
Muenzaniso 3: Kuverenga pH yeAcid Isina Simba
Mubvunzo:
Verenga pH ye 0,1 M acetic acid (CH₃COOH) solution, ine acid dissociation constant (Ka) ye \( 1,8 \times 10^{-5} \).
Kukurukurirana:
Asidhi asina simba haasangani zvachose mumushonga. Kuti tiverenge pH, tinofanira kutanga taziva huwandu hweH⁺ ions tichishandisa kukosha kweKa.
\[ CH_3COOH \rightleftharpoons H^+ + CH_3COO^- \]
Kana \( x \) iri huwandu hweH⁺ hunogadzirwa:
\[ Ka = \frac{{[H^+][CH_3COO^-]}}{{[CH_3COOH]}} \]
\[ Ka = \frac{{x \cdot x}}{{0,1 – x}} \]
Sezvo iri asidi isina simba, fungidzira kuti \( x \) idiki zvikuru zvekuti \( 0,1 - x \approx 0,1 \):
\[ 1,8 \kawa 10^{-5} = \frac{x^2}{0,1} \]
\[ x^2 = 1,8 \kawa 10^{-6} \]
\[ x = \sqrt{1,8 \kawa 10^{-6}} \]
\[ x \inenge 1,34 \kawa 10^{-3} \]
Kuwanda kwema H⁺ ions kuri pa \( 1,34 \times 10^{-3} \):
\[ \text{pH} = -\log[H^+] \]
\[ \text{pH} = -\log(1,34 \times 10^{-3}) \]
\[ \text{pH} \inenge 2,87 \]
Saka, pH ye 0,1 M CH₃COOH solution inenge 2,87.
Muenzaniso Mubvunzo 4: Kuverenga pH yeWeak Base
Mubvunzo:
Verenga pH ye 0,05 M ammonia (NH₃) solution, ine base dissociation constant (Kb) ye \( 1,8 \times 10^{-5} \).
Kukurukurirana:
Mabhesi asina kusimba haaparadzanise zvachose mumhinduro. Kuti tiverenge pH, tinofanira kutanga taziva huwandu hweOH⁻ ions tichishandisa kukosha kweKb.
\[ NH_3 + H_2O \rightleftharpoons NH_4^+ + OH^- \]
Kana \( x \) iri huwandu hweOH⁻ hunogadzirwa:
\[ Kb = \frac{{[NH_4^+][OH^-]}}{{[NH_3]}} \]
\[ Kb = \frac{{x \cdot x}}{{0,05 – x}} \]
Ngatitii \( x \) idiki zvikuru zvekuti \( 0,05 – x \approx 0,05 \):
\[ 1,8 \kawa 10^{-5} = \frac{x^2}{0,05} \]
\[ x^2 = 9,0 \kawa 10^{-7} \]
\[ x = \sqrt{9,0 \kawa 10^{-7}} \]
\[ x \inenge 9,49 \kawa 10^{-4} \]
Kuwanda kwema OH⁻ ions kuri pa \( 9,49 \times 10^{-4} \):
\[ \text{pOH} = -\log[OH^-] \]
\[ \text{pOH} = -\log(9,49 \times 10^{-4}) \]
\[ \text{pOH} \inenge 3,02 \]
pH ne pOH zvakabatana ne equation:
\[ \text{pH} + \text{pOH} = 14 \]
\[ \mashoko{pH} = 14 – 3,02 \]
\[ \text{pH} \inenge 10,98 \]
Muenzaniso Mubvunzo 5: Kusagadzikana kweAcids neBases
Mubvunzo:
Ndeupi huwandu hwemhinduro yeNaOH ye0,1 M inodiwa kuti 50 mL yemhinduro yeHCl ye0,1 M irege kushanda?
Kukurukurirana:
Kupindirana kwekusagadzikana pakati peasidhi nehwaro kunogadzira mvura nemunyu:
\[ HCl + NaOH \kurudyi NaCl + H_2O \]
Huwandu hwemamota eHCl:
\[ n_{HCl} = Molarity \times Vhoriyamu \]
\[ n_{HCl} = 0,1 \, M \kawa 0,05 \, L \]
\[ n_{HCl} = 0,005 \, mol \]
Nekuti mole yega yega yeHCl inosangana ne mole imwe yeNaOH, huwandu hwema moles eNaOH hunodiwa hwakafanana, kureva 0,005 moles.
Vhoriyamu yeNaOH inodiwa:
\[ n_{NaOH} = Molarity_{NaOH} \nguva Vhoriyamu \]
\[ Vhoriyamu_{NaOH} = \frac{n_{NaOH}}{Molarity_{NaOH}} \]
\[ Vhoriyamu_{NaOH} = \frac{0,005 \, mol}{0,1 \, M} \]
\[ Vhoriyamu_{NaOH} = 0,05 \, L \]
\[ Vhoriyamu_{NaOH} = 50 \, mL \]
Saka, 50 mL ye 0,1 M NaOH solution inodiwa kuti 50 mL ye 0,1 M HCl solution ishande zvakanaka.
Nekukurukura mibvunzo iri pamusoro apa, tinotarisira kunzwisisa zvakajeka hunhu nepfungwa dzemaasidhi nemabhesi. Hunhu nepfungwa idzi dzakakosha zvikuru mukushandiswa kwakasiyana-siyana kwemakemikari kwezuva nezuva, kubva pakuongorora marabhoritari kusvika kumaindasitiri.
