Tauira o tētahi Pātai Kōrero mō te Stoichiometry Otinga
Ko te Stoikiometry he peka o te matū e ako ana i te whanaungatanga tauanga i waenga i ngā matū tauhohe me ngā hua i roto i tētahi tauhohenga matū. He motuhake ake te stoikiometry otinga, nā te mea e aro ana ki ngā tauhohenga matū e puta ana i roto i tētahi whakarewa, ko te wai te nuinga. I roto i tēnei tuhinga, ka matapakihia e mātou ngā tauira raruraru e pā ana ki te stoikiometry otinga kia pai ake ai te mārama ki tēnei ariā.
Ngā Ariā Taketake o te Stoichiometry Otinga
I mua i te urunga atu ki ngā tauira pātai, me mārama tātou ki ētahi ariā matua:
1. Te Molarity (M): Ko te kukū o te otinga ka whakaaturia i roto i te molarity. Ko te Molarity te maha o ngā mole o te matū solute mō ia rita o te otinga (mol/L).
2. Mol: Te waeine o te nui o te matū kei roto ko ngā matūriki o te tau Avogadro (6.022 x 10²³).
3. Rōrahi Otinga: I te nuinga o te wā ka inehia ki ngā rita (L).
Nā tēnei māramatanga taketake, kua rite tātou ki te neke atu ki ngā tauira rapanga me ngā otinga.
Tauira Pātai 1: Te Tatau i te Molarity o tētahi Otinga
Pātai:
I te mea e 5 karamu o te NaCl (Sodium Chloride) ka whakarewaina ki roto i te 250 mL o te wai, he aha te molarity o te otinga NaCl?
Otinga:
1. Tātaihia te maha o ngā mole o te NaCl:
– Taumaha ngota (BM) o te NaCl: Na (23) + Cl (35.5) = 58.5 g/mol
– Te maha o ngā mole = Papatipu / BM
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Te maha o ngā mole o te NaCl = 5 karamu / 58.5 karamu/mol ≈ 0.0855 mol
""
2. Tahurihia te rōrahi o te otinga mai i te mL ki te L:
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Te rōrahi o te otinga = 250 mL = 0.250 L
""
3. Tātaihia te molarity (M):
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Te Molarity (M) = Te maha o ngā mole / Te rōrahi o te otinga
= 0.0855 mol / 0.250 L
≈ 0.342 M
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Nō reira, ko te molarity o te otinga NaCl he 0.342 M.
Tauira Pātai 2: Tauhohenga Whakakore
Pātai:
E hia te rōrahi o te otinga HCl 0.5 M e hiahiatia ana hei whakakore i te 50 mL o te otinga NaOH 0.1 M?
Otinga:
Ngā tauhohenga e puta ana:
""
HCl + NaOH → NaCl + H₂O
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Ka puta tēnei tauhohenga i te ōwehenga 1:1.
1. Tātaihia te maha o ngā mole o te NaOH:
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Te maha o ngā mole o te NaOH = Te Molarity x Te Rōrahi
= 0.1 M x 0.050 L
= 0.005 mol
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2. Nā te mea ko te ōwehenga tauhohenga he 1:1, ko te maha o ngā ira o te HCl = te maha o ngā ira o te NaOH = 0.005 mol.
3. Tātaihia te rōrahi o te otinga HCl e hiahiatia ana:
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Te rōrahi o te HCl = Te maha o ngā mole / Te mōrahi
= 0.005 mol / 0.5 M
= 0.01 rita (10 mL rānei)
""
Nō reira, ko te rōrahi o te otinga HCl 0.5 M he 10 mL.
Tauira Pātai 3: Te Whakatōpūtanga Waikawa-Pūtake
Pātai:
Ka tātaitia he otinga 25 mL o te CH₃COOH (waikawa acetic) ki te otinga 0.1 M NaOH ki te pūwāhi ōrite. E hiahiatia ana te 30 mL o te otinga NaOH hei tae atu ki te pūwāhi ōrite. Tātaihia te molarity o te otinga CH₃COOH.
Otinga:
Ngā tauhohenga e puta ana:
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CH₃COOH + NaOH → CH₃COONa + H₂O
""
Ka puta hoki tēnei tauhohenga i te ōwehenga 1:1.
1. Tātaihia te maha o ngā mole o te NaOH i whakamahia:
""
Te maha o ngā mole o te NaOH = Te Molarity x Te Rōrahi
= 0.1 M x 0.030 L
= 0.003 mol
""
2. He rite te maha o ngā mole o te CH₃COOH ki te maha o ngā mole o te NaOH i tauhohe (ōwehenga 1:1):
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Te maha o ngā mole o te CH₃COOH = 0.003 mol
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3. Tātaihia te mōrahi o te CH₃COOH:
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Te Molarity (M) = Te maha o ngā mole / Te Rōrahi
= 0.003 mol / 0.025 L
= 0.12 M
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Nō reira, ko te mōroiti o te otinga CH₃COOH he 0.12 M.
Tauira Pātai 4: Te Whakarewatanga o te Otinga
Pātai:
He aha te nui o te wai me tāpiri hei whakaranu i te 100 mL o te otinga H₂SO₄ 1 M kia eke tōna kukū ki te 0.25 M?
Otinga:
1. Whakamahia te tātai whakakōkī (M₁V₁ = M₂V₂):
– M₁ = 1 M
– V₁ = 100 mL
– M₂ = 0.25 M
2. Tātaihia te V₂:
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M₁V₁ = M₂V₂
1 M x 100 mL = 0.25 M x V₂
V₂ = (1 x 100) / 0.25
= 400 mL
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3. Tātaihia te rahinga wai hei tāpiri:
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Te rōrahi wai i tāpirihia = V₂ – V₁
= 400 mL – 100 mL
= 300 mL
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Nō reira, me tāpiri he 300 mL o te wai hei whakakorikori i te wairewa H₂SO₄ mai i te 1 M ki te 0.25 M.
Tauira Pātai 5: Tauhohenga Ua
Pātai:
E hia karamu o te matūriki AgCl ka puta ina konatunatua te 100 mL o te wairewa 0.1 M AgNO₃ ki te 100 mL o te wairewa 0.1 M NaCl?
Otinga:
Ngā tauhohenga e puta ana:
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AgNO₃ + NaCl → AgCl (pūpū) + NaNO₃
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Ka puta tēnei tauhohenga i te ōwehenga 1:1.
1. Tātaihia te maha o ngā mole o AgNO₃ me NaCl:
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Te maha o ngā mole o te AgNO₃ = Te Molarity x Te Rōrahi
= 0.1 M x 0.100 L
= 0.01 mol
Te maha o ngā mole o te NaCl = Te Molarity x Te Rōrahi
= 0.1 M x 0.100 L
= 0.01 mol
""
2. Nā te mea ko te ōwehenga tauhohenga he 1:1, ko te maha o ngā mole o te AgCl i hangaia = Te maha o ngā mole o te AgNO₃, o te NaCl rānei:
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Te maha o ngā mole o AgCl = 0.01 mol
""
3. Tātaihia te papatipu o AgCl:
– Taumaha ngota o te AgCl = Ag (107.87) + Cl (35.45) = 143.32 karamu/mol
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Papatipu o AgCl = Te maha o ngā mole x BM
= 0.01 mol x 143.32 karamu/mol
= 1.4332 karamu
""
Nō reira, ko te papatipu o te matūriki AgCl i hangaia he 1.4332 karamu.
Whakamutunga
Kua matapakihia e tēnei tuhinga ētahi tauira raruraru me ngā otinga e pā ana ki te stoichiometry otinga, tae atu ki te tatau i te molarity, ngā tauhohenga whakakorekore, ngā irahiko waikawa-pūtake, te waimehatanga, me te hanganga matū. Mā te mārama ki ēnei tauira, ka taea e tātou te mārama ake ki te whakamahinga o te ariā o te stoichiometry otinga i roto i ngā āhuatanga o te ao tūturu. Ehara i te mea he mea nui anake te stoichiometry otinga i roto i te ako matū engari he whānui hoki ngā tono i roto i ngā momo mara pērā i te rongoā, te matū koiora, me te umanga matū.
