Lipotso tsa Mehlala le Puisano ea Arrhenius Acids le Bases
Li-acid le metheo ke likhopolo tsa motheo k'hemistri. E 'ngoe ea likhopolo-taba tse tsebahalang haholo ho hlalosa boitšoaro ba li-acid le metheo ke khopolo-taba ea Arrhenius. Ho ea ka Arrhenius, asiti ke motsoako oo, ha o qhibiliha ka metsing, o hlahisang li-ion tsa H⁺ (kapa H₃O⁺), ha motheo e le motsoako oo, ha o qhibiliha ka metsing, o hlahisang li-ion tsa OH⁻. Sehloohong sena, re tla tšohla mehlala e 'maloa ea mathata mabapi le li-acid le metheo ho latela khopolo-taba ea Arrhenius, hammoho le litharollo tsa tsona.
Mohlala oa Potso ea 1
Potso:
Tharollo ea hydrochloric acid (HCl) ea 0,1 M e qhibiliha ka metsing. Bala mahloriso a li-ion tsa H⁺ ka har'a tharollo.
Puisano:
Ho ya ka khopolo-taba ya Arrhenius, HCl ke asiti hobane e hlahisa di-ion tsa H⁺ ha e qhibilihiswa ka metsing. Tekanyo ya ionization bakeng sa HCl ka metsing ke e latelang:
\[ \text{HCl} \ho \text{H}^+ + \text{Cl}^- \]
Khakanyo ea pele ea HCl ke 0,1 M. Kaha HCl ke asiti e matla e ioning ka botlalo ka har'a tharollo ea metsi, molek'hule e 'ngoe le e 'ngoe ea HCl e tla hlahisa ioni e le 'ngoe ea H⁺ le ioni e le 'ngoe ea Cl⁻. Ka hona, khakanyo ea li-ion tsa H⁺ ka har'a tharollo le eona e lekana le khakanyo ea HCl, e leng:
\[ [\mongolo{H}^+] = 0,1 \mongolo{M} \]
Kahoo, mahloriso a li-ion tsa H⁺ ka har'a tharollo ea HCl ea 0,1 M ke 0,1 M.
Mohlala oa Potso ea 2
Potso:
Bala pH ea tharollo ea asiti ea nitric ea 0,01 M (HNO₃).
Puisano:
HNO₃ ke asiti e matla e ionishang ka botlalo ka metsing, kahoo equation ea ionization bakeng sa HNO₃ ke e latelang:
\[ \text{HNO}_3 \ho \text{H}^+ + \text{NO}_3^- \]
Khakanyo e fanoeng ea HNO₃ ke 0,01 M. Kaha HNO₃ ke asiti e matla, molek'hule e 'ngoe le e 'ngoe ea HNO₃ e tla hlahisa ioni e le 'ngoe ea H⁺. Ka hona, khakanyo ea li-ion tsa H⁺ ka har'a tharollo e lekana le khakanyo ea HNO₃, e leng:
\[ [\mongolo{H}^+] = 0,01 \mongolo{M} \]
pH e ka baloa ho sebelisoa foromo:
\[ \text{pH} = -\log [\text{H}^+] \]
Ka ho kenya mahloriso a li-ion tsa H⁺ foromong, re fumana:
\[ \text{pH} = -\log (0,01) = -\log (10^{-2}) = 2 \]
Kahoo, pH ea tharollo ea HNO₃ ea 0,01 M ke 2.
Mohlala oa Potso ea 3
Potso:
Fumana hore na li-ion tsa OH⁻ li hokahane hakae ka har'a tharollo ea NaOH ea 0,05 M.
Puisano:
NaOH ke motheo o matla o ionizes ka botlalo ka metsing, kahoo equation ea ionization bakeng sa NaOH ke e latelang:
\[ \mongolo{NaOH} \ho \ mongolo{Na}^+ + \mongolo{OH}^- \]
Khakanyo ea NaOH e fanoeng ke 0,05 M. Kaha NaOH ke motheo o matla, molek'hule e 'ngoe le e 'ngoe ea NaOH e tla hlahisa OH⁻ ion e le 'ngoe. Ka hona, khakanyo ea OH⁻ ions ka har'a tharollo e lekana le khakanyo ea NaOH, e leng:
\[ [\mongolo{OH}^-] = 0,05 \mongolo{M} \]
Kahoo, mahloriso a li-ion tsa OH⁻ ka har'a tharollo ea 0,05 M NaOH ke 0,05 M.
Mohlala oa Potso ea 4
Potso:
Bala pH ea tharollo ea 0,01 M KOH.
Puisano:
KOH ke motheo o matla o ionisang ka botlalo ka metsing. Tekanyo ea ionization bakeng sa KOH ka metsing ke e latelang:
\[ \text{KOH} \ho \text{K}^+ + \text{OH}^- \]
Khakanyo e fanoeng ea KOH ke 0,01 M. Kaha KOH ke motheo o matla, molek'hule ka 'ngoe ea KOH e tla hlahisa ion e le 'ngoe ea OH⁻. Ka hona, khakanyo ea li-ion tsa OH⁻ ka har'a tharollo e lekana le khakanyo ea KOH, e leng:
\[ [\mongolo{OH}^-] = 0,01 \mongolo{M} \]
pH ke tekanyo ea mahloriso a li-ion tsa H⁺ ka har'a tharollo. Re ka sebelisa kamano pakeng tsa li-ion tsa pH, H⁺, le OH⁻ tse fanoeng ke sehlahisoa sa li-ion tsa metsi (Kw):
\[ \text{Kw} = [\text{H}^+][\text{OH}^-] = 1 \times 10^{-14} \]
Ha re tseba boleng ba [OH⁻], re ka bala [H⁺]:
\[ [\text{H}^+] = \frac{\text{Kw}}{[\text{OH}^-]} = \frac{1 \times 10^{-14}}{0,01} = 1 \times 10^{-12} \text{M} \]
pH e ka baloa ho sebelisoa foromo:
\[ \text{pH} = -\log [\text{H}^+] \]
Ka ho kenya mahloriso a li-ion tsa H⁺ foromong, re fumana:
\[ \text{pH} = -\log (1 \makgetlo a 10^{-12}) = 12 \]
Kahoo, pH ea tharollo ea 0,01 M KOH ke 12.
Mohlala oa Potso ea 5
Potso:
Tharollo e na le pH = 3. Bala mahloriso a li-ion tsa H⁺ ka har'a tharollo.
Puisano:
pH ke tekanyo ea mahloriso a li-ion tsa H⁺ ka har'a tharollo 'me e ka hlalosoa ka mokhoa o latelang:
\[ \text{pH} = -\log [\text{H}^+] \]
Ho bala mahloriso a li-ion tsa H⁺, re fetola foromo ho:
\[ [\text{H}^+] = 10^{-\text{pH}} \]
Ka ho kenya boleng ba pH bo fanoeng, re fumana:
\[ [\mongolo{H}^+] = 10^{-3} = 0,001 \mongolo{M} \]
Kahoo, mahloriso a li-ion tsa H⁺ ka har'a tharollo e nang le pH = 3 ke 0,001 M.
Mohlala oa Potso ea 6
Potso:
Tharollo ea NH₄OH e na le mahloriso a 0,1 M. Bala pH ea tharollo haeba boleng ba Kb bakeng sa NH₄OH e le 1,8 x 10⁻⁵.
Puisano:
NH₄OH ke motheo o fokolang o sa ioning ka botlalo ka metsing. Tekanyo ea ionization bakeng sa NH₄OH ka metsing ke e latelang:
\[ \text{NH}_4\text{OH} \leftrightarrow \text{NH}_4^+ + \text{OH}^- \]
Nako e tloaelehileng ea tekano bakeng sa ionization ea NH₄OH e bitsoa Kb 'me e fanoa ke:
\[ K_b = \frac{[\text{NH}_4^+][\text{OH}^-]}{[\text{NH}_4\text{OH}} \]
Kaha NH₄OH ke motheo o fokolang, re sebedisa Kb ho bala mahloriso a di-ion tsa OH⁻. Ha re nahana hore \(x\) ke mahloriso a NH₄OH e nang le ionized, equation ya ionization e ba:
\[ K_b = \frac{x^2}{0,1 – x} \hoo e ka bang \frac{x^2}{0,1} \]
Kaha boleng ba Kb bo nyane haholo, re nahana hore \(0,1 – x \hoo e ka bang 0,1\):
\[ 1,8 \makgetlo a 10^{-5} = \frac{x^2}{0,1} \]
\[ x^2 = 1,8 \makgetlo a 10^{-6} \]
\[ x = \sqrt{1,8 \makgetlo a 10^{-6}} \]
\[ x \hoo e ka bang 1,34 \makgetlo a 10^{-3} \mongolo{ M} \]
Kahoo, mahloriso a li-ion tsa OH⁻ ke \(1,34 \times 10^{-3} \text{ M}\).
Ho tsoa mahlorisong ana, re ka bala mahloriso a li-ion tsa H⁺ re sebelisa Kw:
\[ [\text{H}^+] = \frac{1 \times 10^{-14}}{1,34 \times 10^{-3}} \]
\[ [\text{H}^+] = 7,46 \times 10^{-12} \text{M} \]
pH:
\[ \text{pH} = -\log (7,46 \makgetlo a 10^{-12}) \]
\[ \text{pH} \hoo e ka bang 11,13 \]
Kahoo, pH ea tharollo ea 0,1 M NH₄OH e ka ba 11,13.
Qetello
Khopolo-taba ea Arrhenius e fana ka motheo oa bohlokoa oa ho utloisisa hore na li-acid le metheo li itšoara joang tharollong. Puisanong ena, re shebile mehlala e 'maloa ea mathata a bontšang kamoo likhopolo tsena li ka sebelisoang kateng ho bala mahloriso a li-ion tsa H⁺ le OH⁻ le pH ea litharollo tse fapaneng. Ho utloisisa khopolo-taba ena ho bohlokoa bakeng sa mang kapa mang ea phehellang mosebetsi oa k'hemistri, ebang ke sekolong se phahameng kapa boemong ba thuto e phahameng.
