Mienzaniso yeMibvunzo Inokurukura Simba uye pH yeAcids neBases
Simba reacid-base uye pH zvinhu zvakakosha mukemikari, kunyanya munyaya dzeacids nebases. Muchinyorwa chino, tichakurukura kuti tingaziva sei simba reacid nebase uye kuverenga pH yemhinduro tichishandisa mienzaniso yakati wandei yezvinetso.
Nhanganyaya kuAcids neBases
Assam
Asidhi chinhu chinogona kuburitsa mahydrogen ions (H⁺) kana chanyungudutswa mumvura. Zvichienderana nekukwanisa kwadzo kuburitsa maH⁺ ions, maacids akakamurwa kuita mhando mbiri:
1. Asidhi Yakasimba: Asidhi inoparadzanisa 100% mumushonga, ichiburitsa H⁺ ions zvachose. Mienzaniso: Hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃).
2. Asidhi isina simba: Asidhi inongopatsanuka zvishoma mumushonga, mamwe mamorekuru chete ndiwo anoburitsa maH⁺ ions. Mienzaniso: Acetic acid (CH₃COOH), carbonic acid (H₂CO₃), hydrocyanic acid (HCN).
base
Hwaro chinhu chinogona kuburitsa maion ehydroxide (OH⁻) kana chanyungudutswa mumvura. Zvichienderana nekukwanisa kwadzo kuburitsa maion eOH⁻, mabass akapatsanurwawo kuita mhando mbiri:
1. Hwaro hwakasimba: Hwaro hunoparadzanisa 100% mumushonga, zvichiburitsa ma OH⁻ ions zvachose. Mienzaniso: Sodium hydroxide (NaOH), potassium hydroxide (KOH).
2. Hwaro husina kusimba: Hwaro hunongopatsanuka zvishoma mumushonga, mamwe mamorekuru chete ndiwo anoburitsa ma OH⁻ ions. Mienzaniso: Ammonia (NH₃), magnesium hydroxide (Mg(OH)₂).
pfungwa ye pH
pH chiyero cheacidity kana alkalinity yemushonga. Inotsanangurwa se negative logarithm yehuwandu hwehydrogen ion (H⁺):
\[ \text{pH} = – \log [H⁺] \]
Kune mhinduro huru, pOH inoshandiswawo, iyo inotsanangurwa se negative logarithm ye hydroxide ion (OH⁻) concentration:
\[ \text{pOH} = – \log [OH⁻] \]
Hukama huripo pakati pe pH ne pOH ndehwekuti:
\[ \text{pH} + \text{pOH} = 14 \]
pH 7 inonzi neutral, pH iri pasi pe7 inonzi acidic, uye pH iri pasi pe7 inonzi alkaline.
Mibvunzo yemuenzaniso nekukurukurirana
Muenzaniso Mubvunzo 1: Kuverenga pH yeAcid Yakasimba
Mubvunzo: Tsvaga pH ye 0,01 M HCl solution.
Kukurukurirana: HCl iasidhi yakasimba iyo inozopatsanurwa zvachose kuita H⁺ neCl⁻ ions. Sezvo ine 1:1 molarity pakati peHCl neH⁺, huwandu hweH⁺ i0,01 M.
\[ \text{pH} = – \log [H⁺] \]
\[ \text{pH} = – \log (0,01) \]
\[ \mashoko{pH} = 2 \]
Saka, pH ye 0,01 M HCl solution i2.
Muenzaniso Mubvunzo 2: Kuverenga pH yeAcid Isina Simba
Mubvunzo: Tsvaga pH ye 0,1 M CH₃COOH (acetic acid) solution kana \( K_a \) ye CH₃COOH iri \( 1,8 \times 10^{-5} \).
Kukurukurirana: Asidhi asina simba haaparadzanise zvachose, saka tinoshandisa chinhu chinogara chichiparadzanisa acid ( \( K_a \) ) kuti tione huwandu hweH⁺. Kune CH₃COOH, equation yekuparadzanisa ndeiyi:
\[ \text{CH₃ COOH} \rightleftharpoons \text{H⁺} + \text{CH₃ COO⁻} \]
Kubva pamutemo we "buffer solution", tinofunga kuti \( x \) ndiyo huwandu hweH⁺ ions dzakaumbwa:
\[ K_a = \frac{ [H⁺][CH₃ COO⁻] }{ [CH₃ COOH] } \]
\[ 1,8 \kawa 10^{-5} = \frac{ (x)(x) }{ 0,1 – x } \]
Sezvo \( x \) iri diki zvikuru kana tichienzanisa ne 0,1 M, tinogona kufuratira x mu denominator:
\[ 1,8 \kawa 10^{-5} \approx \frac{ x^2 }{ 0,1 } \]
\[ x^2 \inenge 1,8 \kawa 10^{-6} \]
\[ x \approx \sqrt{ 1,8 \times 10^{-6} } \]
\[ x \inenge 1,34 \kawa 10^{-3} \]
Saka, huwandu hweH⁺ ndi \( 1,34 \times 10^{-3} \):
\[ \text{pH} = – \log [H⁺] \]
\[ \text{pH} = – \log (1,34 \kawa 10^{-3}) \]
\[ \text{pH} \inenge 2,87 \]
Saka, pH ye 0,1 M CH₃COOH solution inenge 2,87.
Muenzaniso Mubvunzo 3: Kuverenga pH yeBase Rakasimba
Mubvunzo: Tsvaga pH ye 0,01 M NaOH solution.
Kukurukurirana: NaOH ihwaro hwakasimba huchapatsanurwa zvachose kuita maNa⁺ neOH⁻ ions. Sezvo iine 1:1 molarity pakati peNaOH neOH⁻, huwandu hweOH⁻ i0,01 M.
\[ \text{pOH} = – \log [OH⁻] \]
\[ \text{pOH} = – \log (0,01) \]
\[ \mashoko{pOH} = 2 \]
Kushandisa hukama \( \text{pH} + \text{pOH} = 14 \):
\[ \text{pH} = 14 – \text{pOH} \]
\[ \mashoko{pH} = 14 – 2 \]
\[ \mashoko{pH} = 12 \]
Saka, pH ye 0,01 M NaOH solution i12.
Muenzaniso Mubvunzo 4: Kuverenga pH yeWeak Base
Mubvunzo: Tsvaga pH ye 0,1 M NH₃ solution kana \( K_b \) yeNH₃ iri \( 1,8 \times 10^{-5} \).
Kukurukurirana: Mabhesi asina kusimba haaparadzanise zvachose, saka tinoshandisa chinoramba chichibatanidzwa chebase dissociation ( \( K_b \) ) kuti tione huwandu hweOH⁻. Kune NH₃, dissociation equation ndeiyi:
\[ \text{NH₃ + H₂O} \rightleftharpoons \text{NH₄⁺ + OH⁻} \]
Tichishandisa nzira imwecheteyo neye weak acids, tinofunga kuti \( y \) ndiyo huwandu hweOH⁻ ions hunoumbwa:
\[ K_b = \frac{ [NH₄⁺][OH⁻] }{ [NH₃] } \]
\[ 1,8 \nguva 10^{-5} = \frac{ (y)(y)}{ 0,1 – y } \]
Tichifunga kuti \( y \) idiki, equation inova:
\[ 1,8 \kawa 10^{-5} \approx \frac{ y^2 }{ 0,1 } \]
\[ y^2 \inenge 1,8 \kawa 10^{-6} \]
\[ y \approx \sqrt{ 1,8 \times 10^{-6} } \]
\[ y \inenge 1,34 \kawa 10^{-3} \]
Kuwanda kweOH⁻ ndiko \( 1,34 \times 10^{-3} \):
\[ \text{pOH} = – \log [OH⁻] \]
\[ \text{pOH} = – \log (1,34 \kawa 10^{-3}) \]
\[ \text{pOH} \inenge 2,87 \]
Kushandisa hukama \( \text{pH} + \text{pOH} = 14 \):
\[ \mashoko{pH} = 14 – 2,87 \]
\[ \text{pH} \inenge 11,13 \]
Saka, pH ye 0,1 M NH₃ solution inenge 11,13.
Mhedziso
Kuziva pH yemushonga uye kunzwisisa simba remaacid nemabhesi ndizvo zvakakosha mukemistri. Maacid nemabhesi akasimba zvinopatsanuka zvachose mumushonga, nepo maacid nemabhesi asina simba zvinopatsanuka zvishoma. Kushandisa \( K_a \) uye \( K_b \) kunoita kuti zvive nyore kuverenga pH yemaacid nemabhesi asina simba. Unyanzvi uhwu hwakakosha pakushandiswa muminda yakasiyana-siyana, kusanganisira makemikari emaindasitiri, emishonga, uye ezvakatipoteredza. Nekunzwisisa pfungwa idzi nekudzidza mienzaniso, tinogona kugadzirisa zviri nyore matambudziko ane chekuita nepH uye simba remaacid-base muhupenyu hwezuva nezuva.
