Ajụjụ Ihe Nlereanya Na-akọwa Ike na pH nke Asịd na Bases
Ike isi acid na pH bụ isiokwu dị mkpa na kemistri, ọkachasị n'ihe gbasara asịd na ntọala. N'isiokwu a, anyị ga-atụle otu esi ekpebi ike asịd na ntọala ma gbakọọ pH nke ngwọta site na iji ọtụtụ nsogbu atụ.
Okwu Mmalite nke Asịd na Bases
Assam
Asịd bụ ihe mejupụtara nke nwere ike iwepụta ion hydrogen (H⁺) mgbe ọ gbazere na mmiri. Dabere na ikike ha nwere iwepụta ion H⁺, a na-ekewa asịd n'ụdị abụọ:
1. Asịd siri ike: Asịd nke na-ekewapụ 100% na mmiri, na-ewepụta ion H⁺ kpamkpam. Ihe atụ: Asịd Hydrochloric (HCl), Asịd Sulfuric (H₂SO₄), Asịd Nitric (HNO₃).
2. Asịd adịghị ike: Asịd nke na-ekewapụ naanị akụkụ ụfọdụ na mmiri, naanị ụfọdụ n'ime molekul na-ewepụta ion H⁺. Ihe atụ: Asịd Acetic (CH₃COOH), carbonic acid (H₂CO₃), hydrocyanic acid (HCN).
Oghara
Ntọala bụ ihe mejupụtara nke nwere ike iwepụta ion hydroxide (OH⁻) mgbe agbazere na mmiri. Dabere na ikike ha nwere ịtọhapụ ion OH⁻, a na-ekewa ntọala ahụ n'ụdị abụọ:
1. Ntọala siri ike: Ntọala nke na-ekewapụ 100% na mmiri, na-ewepụta ion OH⁻ kpamkpam. Ihe atụ: Sodium hydroxide (NaOH), potassium hydroxide (KOH).
2. Ntọala adịghị ike: Ntọala nke na-ekewapụ naanị akụkụ ụfọdụ na mmiri, naanị ụfọdụ n'ime molekul na-ewepụta ion OH⁻. Ihe atụ: Amonia (NH₃), magnesium hydroxide (Mg(OH)₂).
Echiche pH
pH bụ ihe nha nke acidity ma ọ bụ alkalinity nke ihe ngwọta. A na-akọwa ya dị ka logarithm na-adịghị mma nke njupụta hydrogen ion (H⁺):
\[ \text{pH} = – \log [H⁺] \]
Maka ngwọta ndị bụ isi, a na-ejikwa pOH, nke a kọwara dị ka logarithm na-adịghị mma nke njupụta ion hydroxide (OH⁻):
\[ \text{pOH} = – \log [OH⁻] \]
Mmekọrịta dị n'etiti pH na pOH bụ:
\[ \ederede{pH} + \ederede{pOH} = 14 \]
A na-akpọ pH 7 nke na-anọpụ iche, pH nke na-erughị 7 bụ acidic, na pH nke karịrị 7 bụ alkaline.
Ajụjụ na Mkparịta ụka Ihe Nlereanya
Ajụjụ Ihe Nlereanya nke 1: Ịgbakọ pH nke Acid Dị Ike
Ajụjụ: Chọpụta pH nke ihe ngwọta HCl 0,01 M.
Mkparịta ụka: HCl bụ asịd siri ike nke ga-ekewapụ kpamkpam n'ime ion H⁺ na Cl⁻. Ebe ọ bụ na o nwere molarity 1:1 n'etiti HCl na H⁺, njupụta nke H⁺ bụ 0,01 M.
\[ \text{pH} = – \log [H⁺] \]
\[ \ederede{pH} = – \log (0,01) \]
\[ \ederede{pH} = 2 \]
Ya mere, pH nke 0,01 M HCl ngwọta bụ 2.
Ihe atụ Ajụjụ nke 2: Ịgbakọ pH nke Acid Na-adịghị Ike
Ajụjụ: Chọpụta pH nke ngwọta 0,1 M CH₃COOH (acetic acid) ma ọ bụrụ na \( K_a \) nke CH₃COOH bụ \( 1,8 \ugboro 10^{-5} \).
Mkparịta ụka: Asịd ndị na-adịghị ike anaghị ekewapụ kpamkpam, yabụ anyị na-eji usoro nkewapụ asịd (\( K_a \) ) iji chọpụta mkpokọta H⁺. Maka CH₃COOH, usoro nkewapụ bụ:
\[ \ederede{CH₃ COOH} \rightleftharpoons \ederede{H⁺} + \ederede{CH₃ COO⁻} \]
Site na iwu ngwọta nchekwa, anyị chere na \( x \) bụ njupụta nke ion H⁺ e guzobere:
\[ K_a = \frac{ [H⁺][CH₃ COO⁻] }{ [CH₃ COOH] } \]
\[ 1,8 \ugboro 10^{-5} = \frac{ (x)(x) }{ 0,1 – x } \]
Ebe ọ bụ na \( x \) dị obere ma e jiri ya tụnyere 0,1 M, anyị nwere ike ileghara x anya na denominator:
\[ 1,8 \ugboro 10^{-5} \ihe dịka \frac{ x^2 }{ 0,1 } \]
\[ x^2 \ihe dị ka 1,8 \ugboro 10^{-6} \]
\[ x \ihe dị ka \sqrt{ 1,8 \ugboro 10^{-6} } \]
\[ x \ihe dị ka 1,34 \ugboro 10^{-3} \]
Ya mere, njupụta nke H⁺ bụ \( 1,34 \ugboro 10^{-3} \):
\[ \text{pH} = – \log [H⁺] \]
\[ \text{pH} = – \log (1,34 \ugboro 10^{-3}) \]
\[ \ederede{pH} \ihe dịka 2,87 \]
Ya mere, pH nke ihe ngwọta 0,1 M CH₃COOH bụ ihe dịka 2,87.
Ajụjụ Ihe Nlereanya nke 3: Ịgbakọ pH nke Isi Siri Ike
Ajụjụ: Chọpụta pH nke ihe ngwọta NaOH nke 0,01 M.
Mkparịta ụka: NaOH bụ ntọala siri ike nke ga-ekewapụ kpamkpam n'ime ion Na⁺ na OH⁻. Ebe ọ bụ na o nwere molarity 1:1 n'etiti NaOH na OH⁻, njupụta nke OH⁻ bụ 0,01 M.
\[ \text{pOH} = – \log [OH⁻] \]
\[ \text{pOH} = – \log (0,01) \]
\[ \ederede{pOH} = 2 \]
Iji mmekọrịta ahụ \( \text{pH} + \text{pOH} = 14 \):
\[ \text{pH} = 14 – \text{pOH} \]
\[ \ederede{pH} = 14 – 2 \]
\[ \ederede{pH} = 12 \]
Ya mere, pH nke ngwọta NaOH 0,01 M bụ 12.
Ihe atụ Ajụjụ nke 4: Ịgbakọ pH nke isi na-adịghị ike
Ajụjụ: Chọpụta pH nke ngwọta 0,1 M NH₃ ma ọ bụrụ na \( K_b \) nke NH₃ bụ \( 1,8 \ugboro 10^{-5} \).
Mkparịta ụka: Ntọala ndị na-adịghị ike anaghị ekewapụ kpamkpam, yabụ anyị na-eji ntọala nkewapụ isi (\( K_b \) ) iji chọpụta mkpokọta nke OH⁻. Maka NH₃, nhazi nkewapụ bụ:
\[ \ederede{NH₃ + H₂O} \rightleftharpoons \ederede{NH₄⁺ + OH⁻} \]
Site n'iji otu ụzọ ahụ e si eme acid ndị na-adịghị ike, anyị chere na \(y \) bụ njupụta nke ion OH⁻ e mepụtara:
\[ K_b = \frac{ [NH₄⁺][OH⁻] }{ [NH₃] } \]
\[ 1,8 \ ugboro 10 ^ {-5} = \ frac { (y) (y) }{ 0,1 - y } \]
Ọ bụrụ na \( y \) dị obere, nha nhata ahụ ga-aghọ:
\[ 1,8 \ugboro 10^{-5} \ihe dịka \frac{ y^2 }{ 0,1 } \]
\[ y^2 \ihe dị ka 1,8 \ugboro 10^{-6} \]
\[ y \ihe dị ka \sqrt{ 1,8 \ugboro 10^{-6} } \]
\[ y \ihe dị ka 1,34 \ugboro 10^{-3} \]
Ọnụọgụ nke OH⁻ bụ \( ugboro 1,34 10^{-3} \):
\[ \text{pOH} = – \log [OH⁻] \]
\[ \text{pOH} = – \log (1,34 \ugboro 10^{-3}) \]
\[ \ederede{pOH} \ihe dị ka 2,87 \]
Iji mmekọrịta ahụ \( \text{pH} + \text{pOH} = 14 \):
\[ \ederede{pH} = 14 – 2,87 \]
\[ \ederede{pH} \ihe dịka 11,13 \]
Ya mere, pH nke ihe ngwọta 0,1 M NH₃ bụ ihe dịka 11,13.
Mmechi
Ịchọpụta pH nke ngwọta na ịghọta ike nke asịd na ntọala bụ isi ihe dị mkpa na kemistri. Asịd na ntọala siri ike na-ekewapụ kpamkpam na ngwọta, ebe asịd na ntọala ndị na-adịghị ike na-ekewapụ naanị akụkụ. Iji \(K_a \) na \(K_b \) na-eme ka ọ dị mfe ịgbakọ pH nke asịd na ntọala ndị na-adịghị ike. Nkà ndị a dị mkpa maka ojiji n'ọtụtụ ngalaba, gụnyere kemistri ụlọ ọrụ mmepụta ihe, ọgwụ, na gburugburu ebe obibi. Site n'ịghọta echiche na ịmụ ihe atụ, anyị nwere ike idozi nsogbu ndị metụtara pH na ike acid-base na ndụ kwa ụbọchị.
