Misalin Tambayoyin Tattaunawa Game da Gishirin Hydrolysis
Ruwan gishiri wani abu ne da ke tattare da amsawar gishiri da ruwa, yana samar da sinadarin acid ko tushe a matsayin wani abu da ya rage. Wannan tsari galibi muhimmin batu ne a darussan sinadarai domin fahimtar ruwan gishiri zai iya samar da fahimta ta asali game da halayen mafita da kuma taimakawa wajen tantance pH na mafita. A cikin wannan labarin, za mu tattauna misalai da dama na matsaloli da mafita da suka shafi ruwan gishiri.
Ka'idoji na Asali na Ruwan Gishiri
Ruwan gishiri yana faruwa ne lokacin da gishiri ya ruɓe a cikin ruwa kuma ions ɗinsa suna amsawa da ƙwayoyin ruwa don samar da acid ko tushe. Ba duk gishirin ne za su yi ruwa ba; wasu suna tsaka tsaki, ma'ana ba sa canza pH na ruwan. Duk da haka, wasu gishirin na iya samar da mafita na acid ko na asali, ya danganta da tushen acid da tushen da ya samar da gishirin.
Domin fahimtar wannan tsari, yana da muhimmanci a san cewa:
– Gishirin acid mai ƙarfi da tushe mai ƙarfi (kamar NaCl) yawanci ba sa yin hydrolysis kuma maganin yana kasancewa tsaka tsaki.
– Gishirin acid mai rauni da tushe mai ƙarfi (kamar CH3COONa) yawanci suna samar da mafita na asali.
– Gishirin acid mai ƙarfi da tushe mai rauni (kamar NH4Cl) yawanci suna samar da ruwan acid.
– Gishirin acid masu rauni da tushe masu rauni na iya amsawa da ruwa da kuma tantance pH na ƙarshe dangane da ƙarfin acid da tushe.
Tambayoyi da Tattaunawa Samfura
Tambaya ta 1: Hydrolysis na Potassium Acetate (CH3COOK)
Tambaya:
Shin maganin potassium acetate (CH3COOK) mai tsami ne, na asali, ko kuma tsaka tsaki? Rubuta amsawar hydrolysis da ke faruwa kuma ka tantance pH na maganin.
Tattaunawa:
Potassium acetate (CH3COOK) gishiri ne na acid mai rauni (acetic acid, CH3COOH) da kuma tushe mai ƙarfi (potassium hydroxide, KOH). Daga wannan, za mu iya yanke hukuncin cewa maganin CH3COOK mai yiwuwa yana da sauƙi saboda ion acetate (CH3COO⁻) zai iya yin hydrolyze a cikin ruwa.
Amsar ita ce kamar haka:
\[ CH_3COO^- + H_2O \rightleftharpoons CH_3COOH + OH^- \]
Ion ɗin Acetate (CH3COO⁻) suna karɓar protons (H⁺) daga ruwa (H2O) don samar da acetic acid (CH3COOH) da ion hydroxide (OH⁻). Kasancewar ion hydroxide (OH⁻) a cikin ruwan yana sa ya zama mai sauƙi.
Domin tantance pH, muna buƙatar yawan ions na OH⁻. Misali, muna da maganin CH3COOK mai 0,1 M kuma ma'aunin ionization na acetic acid (Ka) shine 1,8 × 10⁻⁵.
Matakan da aka ɗauka sune:
1. Amfani da ma'aunin tushe (Kb) don ion na CH3COO⁻:
\[ K_b = \frac{K_w}{K_a} = \frac{10^{-14}}{1,8 \sau 10^{-5}} = 5,56 \sau 10^{-10} \]
2. Raba ions na CH3COO⁻ a cikin maganin:
\[ K_b = \frac{[CH_3COOH][OH^-]}{[CH_3COO^-]} \]
Bari matakin rabuwa ya zama 'x':
\[ 5,56 \sau 10^{-10} = \frac{x^2}{0,1-x} \]
Idan muka yi watsi da ƙaramin \(x\) a cikin ma'aunin, za mu iya sauƙaƙawa:
\[ x^2 \kimanin 5,56 \sau 10^{-11} \Kiran Dama x = \sqrt{5,56 \sau 10^{-11}} = 7,45 \sau 10^{-6} \]
OH⁻ yawan taro:
\[ [OH^-] = 7,45 \sau 10^{-6} \]
pOH na maganin:
\[ pOH = -\log [OH^-] = -\log (7,45 \sau 10^{-6}) \kimanin 5,13 \]
Amfani da alaƙar da ke tsakanin pH da pOH:
[pH = 14 - pOH = 14 - 5,13 = 8,87 \]
Don haka, maganin CH3COOK yana da sauƙi tare da pH na kusan 8,87.
Tambaya ta 2: Hydrolysis na Ammonium Chloride (NH4Cl)
Tambaya:
Shin maganin ammonium chloride (NH4Cl) mai tsami ne, mai sauƙi, ko kuma mai tsaka tsaki? Rubuta amsawar hydrolysis da ke faruwa kuma ka tantance pH na maganin.
Tattaunawa:
Ammonium chloride (NH4Cl) gishiri ne na acid mai ƙarfi (HCl) da kuma tushe mai rauni (NH3). Daga wannan, za mu iya yanke hukuncin cewa maganin yana da acid saboda ammonium ion (NH4⁺) zai iya yin hydrolyze a cikin ruwa.
Amsar ita ce kamar haka:
\[ NH_4^+ + H_2O \rightleftharpoons NH_3 + H_3O^+ \]
Ion na Ammonium (NH4⁺) suna ba da protons (H⁺) ga ƙwayoyin ruwa (H2O) don samar da ammonia (NH3) da ion na hydronium (H3O⁺). Kasancewar ion na hydronium (H3O⁺) a cikin wannan maganin yana sa maganin ya zama mai acidic.
Misali, muna da maganin NH4Cl na 0,1 M. Ma'aunin ionization na tushe (Kb) na NH3 shine 1,8 × 10⁻⁵.
Matakan da aka ɗauka sune:
1. Amfani da ma'aunin acid (Ka) don ion na NH4⁺:
\[ K_a = \frac{K_w}{K_b} = \frac{10^{-14}}{1,8 \sau 10^{-5}} = 5,56 \sau 10^{-10} \]
2. Raba ions na NH4⁺ a cikin ruwan magani:
\[ K_a = \frac{[NH_3][H_3O^+]}{[NH_4^+]} \]
Bari matakin rabuwa ya zama 'x':
\[ 5,56 \sau 10^{-10} = \frac{x^2}{0,1-x} \]
Idan muka yi watsi da ƙaramin \(x\) a cikin ma'aunin, za mu iya sauƙaƙawa:
\[ x^2 \kimanin 5,56 \sau 10^{-11} \Kiran Dama x = \sqrt{5,56 \sau 10^{-11}} = 7,45 \sau 10^{-6} \]
Yawan H3O⁺:
\[ [H_3O^+] = 7,45 \sau 10^{-6} \]
pH na maganin:
\[ pH = -\log [H_3O^+] = -\log (7,45 \sau 10^{-6}) \kimanin 5,13 \]
Don haka, maganin NH4Cl yana da acidic tare da pH na kimanin 5,13.
A cikin misalan biyu da ke sama, mun ga yadda gano nau'in hydrolysis zai iya taimakawa wajen tantance yanayin mafita. Ta hanyar amfani da ma'aunin daidaiton ionization (Ka ko Kb) da wasu zato masu sauƙi, za mu iya magance waɗannan matsalolin cikin sauƙi.
Wannan tattaunawa game da matsalolin hydrolysis na gishiri ba wai kawai tana horar da ƙwarewar nazari a cikin lissafin lissafi ba, har ma tana zurfafa fahimtar mahimman ra'ayoyi na sinadaran mafita. Fahimtar yadda ions na asali daban-daban ke ba da gudummawa ga protons ko masu karɓa ga ƙwayoyin ruwa, da kuma yadda wannan ke shafar pH na mafita, muhimmin abu ne don ƙwarewa a fannoni da yawa na ilimin sinadarai.
