Ajụjụ Ihe Nlereanya Na-ekwu Maka pH nke Acid Dị Ike na Ntọala Dị Ike
pH, ma ọ bụ ike nke hydrogen, bụ ihe atụ nke acidity ma ọ bụ alkalinity nke ngwọta. Nha pH sitere na 0 ruo 14, yana ọnụọgụgụ dị n'okpuru 7 na-egosi ngwọta acid, ọnụọgụgụ dị n'elu 7 na-egosi ngwọta bụ isi, na 7 na-egosi ngwọta na-anọpụ iche. N'isiokwu a, anyị ga-atụle ọtụtụ nsogbu gbasara pH nke asịd siri ike na ntọala siri ike, yana ngwọta ha.
Pendahuluan
Echiche Ndị Dị Mkpa nke pH
pH bụ ihe e ji atụ ihe iji chọpụta acidity ma ọ bụ alkalinity nke ihe ngwọta dabere na mkpokọta nke ion hydrogen (H+). Usoro bụ isi maka ịgbakọ pH bụ:
\[ \ederede{pH} = -\log{[H^+]} \]
Ebe [H+] bụ mkpokọta ion hydrogen na mol/L.
N'aka nke ọzọ, maka ngwọta ndị bụ isi (isi siri ike), anyị nwere ike ịgbakọ pOH mbụ wee tụgharịa ya ka ọ bụrụ pH site na iji usoro ndị a:
\[ \text{pOH} = -\log{[OH^-]} \]
\[ \text{pH} = 14 – \text{pOH} \]
Asịd siri ike na Asịd adịghị ike
Asịd siri ike bụ asịd nke na-agbanwe kpamkpam na mmiri mmiri. Nke a pụtara na ntinye nke ion H+ na mmiri ahụ hà nhata na ntinye nke asịd ahụ n'onwe ya. Ihe atụ nke asịd siri ike bụ HCl (hydrochloric acid), HNO3 (nitric acid), na H2SO4 (sulfuric acid).
N'ụzọ dị iche, asịd ndị na-adịghị ike anaghị agwakọta kpamkpam na mmiri, yabụ ngụkọ pH ha dị mgbagwoju anya ma chọọ echiche nke acidity constant (Ka).
Isi Siri Ike vs Isi Na-adịghị Ike
Dịka asịd siri ike, ntọala siri ike na-agbanwekwa ion kpamkpam n'ime mmiri mmiri. Ihe atụ nke ntọala siri ike bụ NaOH (sodium hydroxide) na KOH (potassium hydroxide).
A na-eme ka ntọala ndị na-adịghị ike bụrụ naanị akụkụ ion ma chọọ echiche nke ntọala basicality (Kb) iji gbakọọ pH.
Ajụjụ na Mkparịta ụka Ihe Nlereanya
Ajụjụ Ihe atụ nke 1: Asịd siri ike
> Gbakọọ pH nke mmiri HCl 0.01 M.
Azịza:
Ebe ọ bụ na HCl bụ asịd siri ike, ọ ga-agbaze kpamkpam na mmiri.
\[ \text{HCl} \rightarrow \text{H}^+ + \text{Cl}^- \]
Ngụkọta nke ion H+ na ngwọta ahụ ga-abụ otu ihe ahụ dị ka ngụkọta nke HCl enyere, ya bụ 0.01 M.
\[ [H^+] = 0.01 \, \ederede{M} \]
Iji usoro pH:
\[ \text{pH} = -\log{[H^+]} = -\log{0.01} = -\log{10^{-2}} = 2 \]
Ya mere, pH nke ngwọta HCl 0.01 M bụ 2.
Ihe atụ Ajụjụ nke 2: Ntọala siri ike
> Gbakọọ pH nke mmiri NaOH nke 0.001 M.
Azịza:
NaOH bụ ntọala siri ike ma ga-agbanwe kpamkpam na ngwọta.
\[ \text{NaOH} \rightarrow \text{Na}^+ + \text{OH}^- \]
Ngụkọta nke OH- ions na ngwọta ahụ bụ otu ihe ahụ dị ka ngụkọta nke NaOH, ya bụ 0.001 M.
\[ [OH^-] = 0.001 \, \ederede{M} = 10^{-3} \, \ederede{M} \]
Gbakọọ POH mbụ:
\[ \text{pOH} = -\log[OH^-] = -\log{10^{-3}} = 3 \]
Gbanwee pOH ka ọ bụrụ pH:
\[ \text{pH} = 14 – \text{pOH} = 14 – 3 = 11 \]
Ya mere, pH nke ngwọta NaOH nke 0.001 M bụ 11.
Ajụjụ Ihe atụ nke 3: Asịd Sulfuric (H2SO4)
> Gbakọọ pH nke ngwọta 0.01 M H2SO4.
Azịza:
H2SO4 bụ asịd siri ike nke nwere usoro abụọ nke ionization. Nkebi nke mbụ:
\[ \ederede{H2SO4} \rightarrow \ederede{H}^+ + \ederede{HSO4}^- \]
Nsonaazụ nke ionization nke ọkwa mbụ bụ nha nhata nke H2SO4 nke 0.01 M maka H+ na HSO4^- ọ bụla. Agbanyeghị, nke mbụ na-emepụta ion H+ abụọ site na otu molekul H2SO4.
Ya mere, mkpokọta [H+] ga-abụ okpukpu abụọ nke ntinye mbụ:
\[ [H^+] = ugboro abụọ 0.01 = 0.02 \]
Iji usoro pH:
\[ \text{pH} = -\log{[H^+]} = -\log{0.02} = -\log{2 \times 10^{-2}} = -(\log{2} + \log{10^{-2}}) \]
Ka ị wee mara,
\[ \log{2} \ihe dị ka 0.301 \]
Ya mere:
\[ \ederede{pH} = -(0.301 + (-2)) = 1.699 \]
Ya mere, pH nke ngwọta 0.01 M H2SO4 bụ ihe dịka 1.699.
Ihe atụ Ajụjụ nke 4: Ntọala siri ike (Ca(OH)2)
> Gbakọọ pH nke ngwọta Ca(OH)2 nke 0.005 M.
Azịza:
Ca(OH)2 bụ ntọala siri ike ma molekul ọ bụla na-enye OH-ion abụọ:
\[ \text{Ca(OH)2} \rightarrow \text{Ca}^{2+} + 2\text{OH}^- \]
Ngụkọta nke OH- ga-abụ okpukpu abụọ nke ngụkọta Ca(OH)2 n'ihi na molekul ọ bụla nke Ca(OH)2 na-emepụta OH-2 abụọ. Ya mere,
\[ [OH^-] = ugboro abụọ 0.005 = 0.01 \, \ederede{M} \]
Gbakọọ POH mbụ:
\[ \text{pOH} = -\log{[OH^-]} = -\log{0.01} = -\log{10^{-2}} = 2 \]
Gbanwee pOH ka ọ bụrụ pH:
\[ \text{pH} = 14 – \text{pOH} = 14 – 2 = 12 \]
Ya mere, pH nke ngwọta Ca(OH)2 nke 0.005 M bụ 12.
Mmechi
N'isiokwu a, anyị atụleela otu esi agbakọ pH maka ọtụtụ ihe atụ nke acid siri ike na ngwọta ntọala siri ike. Cheta na maka asịd ma ọ bụ ntọala siri ike, anyị na-eche na ha bụ ionized kpamkpam na ngwọta. Ya mere, ntinye nke ion H+ maka asịd siri ike na OH- ions maka ntọala siri ike ga-adị ka ntinye mbụ nke asịd ma ọ bụ ntọala, mgbe agbanwechara maka ihe stoichiometric ma ọ bụrụ na ọ dị mkpa. Nke a na-eme ka ngụkọ pH dị mfe site na iji usoro pH na pOH bụ isi.
Ịghọta echiche a dị oke mkpa, ọkachasị n'ọrụ kemịkalụ, ma ọ bụ n'ụlọ nyocha kemịkalụ, ụlọ ọrụ mmepụta ihe, ma ọ bụ ná ndụ kwa ụbọchị. Site na omume na nghọta siri ike, ịgbakọ pH nke asịd siri ike na ntọala ga-abụ ọrụ dị mfe.
