Mafunso ndi Zitsanzo za Arrhenius Acids ndi Bases
Ma asidi ndi maziko ndi mfundo zazikulu mu chemistry. Limodzi mwa malingaliro odziwika bwino ofotokozera khalidwe la ma asidi ndi maziko ndi chiphunzitso cha Arrhenius. Malinga ndi Arrhenius, asidi ndi chinthu chomwe, chikasungunuka m'madzi, chimapanga ma ayoni a H⁺ (kapena H₃O⁺), pomwe maziko ndi chinthu chomwe, chikasungunuka m'madzi, chimapanga ma ayoni a OH⁻. M'nkhaniyi, tikambirana zitsanzo zingapo za mavuto okhudzana ndi ma asidi ndi maziko malinga ndi chiphunzitso cha Arrhenius, pamodzi ndi mayankho awo.
Chitsanzo cha Funso 1
Funso:
Yankho la 0,1 M hydrochloric acid (HCl) limasungunuka m'madzi. Werengani kuchuluka kwa ma H⁺ ayoni mu yankho.
Kukambirana:
Malinga ndi chiphunzitso cha Arrhenius, HCl ndi asidi chifukwa imapanga ma H⁺ ayoni ikasungunuka m'madzi. Equation ya ionization ya HCl m'madzi ndi iyi:
\[ \text{HCl} \to \text{H}^+ + \text{Cl}^- \]
Kuchuluka koyamba kwa HCl ndi 0,1 M. Popeza HCl ndi asidi wamphamvu yomwe imasungunuka kwathunthu mu yankho lamadzi, molekyulu iliyonse ya HCl imapanga H⁺ ion imodzi ndi Cl⁻ ion imodzi. Chifukwa chake, kuchuluka kwa H⁺ ion mu yankho kuli kofanana ndi kuchuluka kwa HCl, komwe ndi:
\[ [\malemba{H}^+] = 0,1 \malemba{M} \]
Kotero, kuchuluka kwa ma H⁺ ions mu yankho la 0,1 M HCl ndi 0,1 M.
Chitsanzo cha Funso 2
Funso:
Werengani pH ya yankho la 0,01 M nitric acid (HNO₃).
Kukambirana:
HNO₃ ndi asidi wamphamvu yomwe imasungunuka kwathunthu m'madzi, kotero equation ya ionization ya HNO₃ ndi iyi:
\[ \text{HNO}_3 \to \text{H}^+ + \text{NO}_3^- \]
Kuchuluka kwa HNO₃ komwe kwaperekedwa ndi 0,01 M. Popeza HNO₃ ndi asidi wamphamvu, molekyulu iliyonse ya HNO₃ imapanga H⁺ ion imodzi. Chifukwa chake, kuchuluka kwa H⁺ ion mu yankho ndi kofanana ndi kuchuluka kwa HNO₃, komwe ndi:
\[ [\malemba{H}^+] = 0,01 \malemba{M} \]
pH ikhoza kuwerengedwa pogwiritsa ntchito fomula iyi:
\[ \text{pH} = -\log [\text{H}^+] \]
Mwa kuyika kuchuluka kwa ma H⁺ ions mu fomula, timapeza:
\[ \text{pH} = -\log (0,01) = -\log (10^{-2}) = 2 \]
Kotero, pH ya yankho la 0,01 M HNO₃ ndi 2.
Chitsanzo cha Funso 3
Funso:
Dziwani kuchuluka kwa ma OH⁻ ions mu yankho la 0,05 M NaOH.
Kukambirana:
NaOH ndi maziko olimba omwe amasungunuka kwathunthu m'madzi, kotero equation ya ionization ya NaOH ndi iyi:
\[ \lemba{NaOH} \ku \lemba{Na}^+ + \mawu{OH}^- \]
Kuchuluka kwa NaOH komwe kwaperekedwa ndi 0,05 M. Popeza NaOH ndi maziko olimba, molekyulu iliyonse ya NaOH imapanga OH⁻ ion imodzi. Chifukwa chake, kuchuluka kwa ma OH⁻ ion mu yankho ndi kofanana ndi kuchuluka kwa NaOH, komwe ndi:
\[ [\malemba{OH}^-] = 0,05 \malemba{M} \]
Kotero, kuchuluka kwa ma OH⁻ ions mu yankho la 0,05 M NaOH ndi 0,05 M.
Chitsanzo cha Funso 4
Funso:
Werengerani pH ya yankho la 0,01 M KOH.
Kukambirana:
KOH ndi maziko olimba omwe amasungunuka kwathunthu m'madzi. Equation ya ionization ya KOH m'madzi ndi iyi:
\[ \text{KOH} \to \text{K}^+ + \text{OH}^- \]
Kuchuluka kwa KOH komwe kwaperekedwa ndi 0,01 M. Popeza KOH ndi maziko olimba, molekyulu iliyonse ya KOH imapanga OH⁻ ion imodzi. Chifukwa chake, kuchuluka kwa ma OH⁻ ion mu yankho ndi kofanana ndi kuchuluka kwa KOH, komwe ndi:
\[ [\malemba{OH}^-] = 0,01 \malemba{M} \]
pH ndi muyeso wa kuchuluka kwa ma ayoni a H⁺ mu yankho. Tingagwiritse ntchito ubale womwe ulipo pakati pa ma ayoni a pH, H⁺, ndi OH⁻ omwe amaperekedwa ndi chinthu cha ma ayoni a madzi (Kw):
\[ \text{Kw} = [\text{H}^+][\text{OH}^-] = 1 \times 10^{-14} \]
Podziwa kufunika kwa [OH⁻], tikhoza kuwerengera [H⁺]:
\[ [\text{H}^+] = \frac{\text{Kw}}{[\text{OH}^-]} = \frac{1 \times 10^{-14}}{0,01} = 1 \times 10^{-12} \text{M} \]
pH ikhoza kuwerengedwa pogwiritsa ntchito fomula iyi:
\[ \text{pH} = -\log [\text{H}^+] \]
Mwa kuyika kuchuluka kwa ma H⁺ ions mu fomula, timapeza:
\[ \text{pH} = -\log (1 \times 10^{-12}) = 12 \]
Kotero, pH ya yankho la 0,01 M KOH ndi 12.
Chitsanzo cha Funso 5
Funso:
Yankho lili ndi pH = 3. Werengani kuchuluka kwa ma H⁺ ayoni mu yankho.
Kukambirana:
pH ndi muyeso wa kuchuluka kwa ma ayoni a H⁺ mu yankho ndipo ikhoza kufotokozedwa ndi fomula iyi:
\[ \text{pH} = -\log [\text{H}^+] \]
Kuti tiwerenge kuchuluka kwa ma H⁺ ions, tisintha fomula kukhala:
\[ [\text{H}^+] = 10^{-\text{pH}} \]
Mukayika pH m'magawo otsatirawa, timapeza:
\[ [\malemba{H}^+] = 10^{-3} = 0,001 \malemba{M} \]
Kotero, kuchuluka kwa ma H⁺ ions mu yankho ndi pH = 3 ndi 0,001 M.
Chitsanzo cha Funso 6
Funso:
Yankho la NH₄OH lili ndi kuchuluka kwa 0,1 M. Werengani pH ya yankho ngati mtengo wa Kb wa NH₄OH ndi 1,8 x 10⁻⁵.
Kukambirana:
NH₄OH ndi maziko ofooka omwe sapanga ioni yonse m'madzi. Equation ya ionization ya NH₄OH m'madzi ndi iyi:
\[ \text{NH}_4\text{OH} \leftrightarrow \text{NH}_4^+ + \text{OH}^- \]
Chokhazikika cha ionization ya NH₄OH chimatchedwa Kb ndipo chimaperekedwa ndi:
\[ K_b = \frac{[\text{NH}_4^+][\text{OH}^-]}{[\text{NH}_4\text{OH}} \]
Popeza NH₄OH ndi maziko ofooka, timagwiritsa ntchito Kb kuwerengera kuchuluka kwa ma OH⁻ ions. Poganiza kuti \(x\) ndi kuchuluka kwa NH₄OH yolumikizidwa, equation ya ionization imakhala:
\[ K_b = \frac{x^2}{0,1 – x} \pafupifupi \frac{x^2}{0,1} \]
Popeza mtengo wa Kb ndi wochepa kwambiri, timaganiza kuti \(0,1 – x \pafupifupi 0,1\):
\[ 1,8 \nthawi 10^{-5} = \frac{x^2}{0,1} \]
\[ x^2 = 1,8 \nthawi 10^{-6} \]
\[ x = \sqrt{1,8 \times 10^{-6}} \]
\[ x \pafupifupi 1,34 \nthawi 10^{-3} \malemba{ M} \]
Kotero, kuchuluka kwa ma OH⁻ ions ndi \(1,34 \times 10^{-3} \text{ M}\).
Kuchokera ku kuchuluka kumeneku, tikhoza kuwerengera kuchuluka kwa ma H⁺ ions pogwiritsa ntchito Kw:
\[ [\text{H}^+] = \frac{1 \times 10^{-14}}{1,34 \times 10^{-3}} \]
\[ [\text{H}^+] = 7,46 \times 10^{-12} \text{M} \]
pH:
\[ \text{pH} = -\log (7,46 \times 10^{-12}) \]
\[ \text{pH} \pafupifupi 11,13 \]
Kotero, pH ya yankho la 0,1 M NH₄OH ndi pafupifupi 11,13.
Mapeto
Chiphunzitso cha Arrhenius chimapereka maziko ofunikira omvetsetsa momwe ma acid ndi ma base amachitira mu yankho. Munkhaniyi, tawona zitsanzo zingapo za mavuto omwe akuwonetsa momwe malingaliro awa angagwiritsidwire ntchito kuwerengera kuchuluka kwa ma H⁺ ndi OH⁻ ions ndi pH ya mayankho osiyanasiyana. Kumvetsetsa chiphunzitsochi ndikofunikira kwa aliyense amene akufuna ntchito ya chemistry, kaya ali kusukulu ya sekondale kapena maphunziro apamwamba.
