Ngā Tauira Pātai mō te Matapaki i te Stoichiometry: Te Mārama ki ngā Kaupapa Taketake me ōna Whakamahinga
Ko te Stoikiometry he peka o te matū e ako ana i ngā ōwehenga tauanga i waenga i ngā matū tauhohe me ngā hua i roto i tētahi tauhohenga matū. Ko te tikanga, he hononga tata te stoikiometry ki te ture tiaki i te papatipu, i whakatakotoria tuatahitia e Antoine Lavoisier. Ko tēnei pūtaiao te pūtake mō ngā ariā maha i roto i te matū, mai i ngā tauhohenga ngāwari ki ngā tukanga ahumahi uaua. Ka matapakihia e tēnei tuhinga ētahi tauira o ngā raruraru stoikiometry, me ō rātou whakamārama me ngā otinga.
Tauira 1: Te Tauhohenga o te Hauwai me te Hāora
Pātai: Tātaihia te maha o ngā ngota wai i hangaia mai i te tauhohenga i waenga i te 4 karamu o te hauwai (H₂) me te 32 karamu o te hāora (O₂).
Kōrero:
1. Te Tuhi i te Whārite Tauhohenga:
Ka taea te tuhi i te tauhohenga i waenga i te hauwai me te hāora hei hanga wai penei:
\[ 2H₂ + O₂ \perematau 2H₂O \]
2. Te Tātai i te Papatipu Molar:
Ko te papatipu molar o te hauwai (H₂) he 2 karamu/mol, ā, ko te papatipu molar o te hāora (O₂) he 32 karamu/mol. Ko te papatipu molar o te wai (H₂O) he 18 karamu/mol.
3. Te Tātai i te Tau o ngā Ira o ngā Tauhohenga:
Te maha o ngā mole o te hauwai:
\[ \text{mol H₂} = \frac{\text{papatipu}}{\text{papatipu molar}} = \frac{4}{2} = 2 \text{ mol} \]
Te maha o ngā mole o te hāora:
\[ \text{mol O₂} = \frac{\text{papatipu}}{\text{papatipu molar}} = \frac{32}{32} = 1 \text{ mol} \]
4. Whakatauhia te Tauhohenga Whakawhāiti:
E ai ki te whārite tauhohenga, e 2 ngā mole o te H₂ ka tauhohe ki te 1 mole o te O₂. I konei, ka ōrite te hauwai (2 ngā mole) ki te 1 mole o te hāora, e ai ki te stoichiometry o te whārite.
5. Te Tātai i te Tau o ngā Hua:
Mai i te whārite tauhohenga, ka puta he 2 ngā mole o te H₂ ka puta he 2 ngā mole o te H₂O. Nā te mea e 2 ā tātou mole o te H₂, ka puta:
\[ 2 \text{ ngā mole H₂O} = 2 \times 6,022 \times 10^{23} \text{ ngā ngota} = 1,2044 \times 10^{24} \text{ ngā ngota} \]
Tauira Pātai 2: Te Tahunga o te Propane
Pātai: E hia te rahinga o te hau waro hauhā (CO₂) ka puta i ngā āhuatanga STP mēnā ka tahuna katoatia te 44 karamu o te propane (C₃H₈)?
Kōrero:
1. Te Tuhi i te Whārite Tauhohenga:
Ko te tahunga tino tika o te propane ko:
\[ C₃H₈ + 5O₂ \rightarrow 3CO₂ + 4H₂O \]
2. Te Tātai i te Papatipu Molar:
Ko te papatipu molar o te propane (C₃H₈) he 44 g/mol. Nō reira, ko te maha o ngā molar o te propane ko:
\[ \text{mol C₃H₈} = \frac{44}{44} = 1 \text{ mol} \]
3. Te Tirohanga i ngā Whakataurite Stoikiometric:
Mai i te whārite matū, ka puta te 1 mol o te C₃H₈ i te 3 mol o te CO₂.
4. Te Tātai i te Rōrahi CO₂:
I ngā āhuatanga STP (pāmahana me te pēhanga paerewa), ko te rōrahi o te 1 mole o te hau he 22,4 L. Nō reira, ko te rōrahi o te CO₂ e whakaputaina ana ko:
\[ \text{Rōrahi CO₂} = 3 \text{ mol} \times 22,4 \text{ L/mol} = 67,2 \text{ L} \]
Tauira Pātai 3: Tauhohenga Titration Waikawa-Pūtake
Pātai: E hia te rōrahi o te otinga NaOH 0,1 M e hiahiatia ana hei whakakore i te 50 mL o te otinga HCl 0,1 M?
Kōrero:
1. Te Tuhi i te Whārite Tauhohenga:
Ko te tauhohenga i waenga i te NaOH me te HCl ko:
\[ NaOH + HCl \perematau NaCl + H₂O \]
2. Te Tātai i te Tau o ngā Ira o te HCl:
\[ \text{mol HCl} = M \times V = 0,1 \text{ M} \times 0,050 \text{ L} = 0,005 \text{ mol} \]
3. Te Tātai i te Tau o ngā Ira o te NaOH:
Mai i te whārite tauhohenga, ka tauhohe te 1 mole o te NaOH ki te 1 mole o te HCl. Nō reira, ko ngā mole o te NaOH e hiahiatia ana he 0,005 mole anō hoki.
4. Te Tātai i te Rōrahi o te NaOH:
\[ \text{Rōrahi o te NaOH} = \frac{\text{mol}}{M} = \frac{0,005 \text{ mol}}{0,1 \text{ M}} = 0,050 \text{ L} = 50 \text{ mL} \]
Tauira Pātai 4: Tauhohenga ki te Tauhohenga Tukunga
Pātai: Mēnā ka tauhohehia te 10 karamu o te konupūmā kāponāte (CaCO₃) ki te 100 mL o te 1 M HCl wairewa, e hia karamu o te hauhā waro (CO₂) ka puta?
Kōrero:
1. Te Tuhi i te Whārite Tauhohenga:
Ko te tauhohenga i waenga i te CaCO₃ me te HCl ko:
\[ CaCO₃ + 2HCl \rightarrow CaCl₂ + H₂O + CO₂ \]
2. Te Tātai i te Papatipu Molar:
Ko te papatipu molar o CaCO₃ he 100 g/mol, ā, ko te papatipu HCl he 36,5 g/mol.
3. Te Tātai i te Tau o ngā Ira o ngā Tauhohenga:
\[ \text{mol CaCO₃} = \frac{10 \text{ g}}{100 \text{ g/mol}} = 0,1 \text{ mol} \]
\[ \text{mol HCl} = 1 \text{ M} \times 0,1 \text{ L} = 0,1 \text{ mol} \]
4. Whakatauhia te Tauhohenga Whakawhāiti:
I runga i te whārite tauhohenga, ka tauhohe te 1 mol o CaCO₃ ki te 2 mol o HCl. I konei, ko CaCO₃ te matū whakawhāiti nā te mea ka hiahiatia te 0,1 mol o CaCO₃ me te 0,2 mol o HCl, engari he 0,1 mol anake o HCl kei a tātou.
5. Te Tātai i te Tau o ngā Hua:
Ki te 0,1 mol o te HCl, ka tauhohe te 0,05 mol anake o te CaCO₃, ka puta he 0,05 mol o te CO₂.
6. Te Tātai i te Papatipu o te CO₂:
Ko te papatipu molar o te CO₂ he 44 g/mol. Nō reira, ko te papatipu o te CO₂ i hangaia ko:
\[ \text{papatipu o te CO₂} = 0,05 \text{ mol} \times 44 \text{ g/mol} = 2,2 \text{ g} \]
Whakamutunga
Ko te mārama ki te stoichiometry me mōhio ki te papatipu molar, ngā whārite tauhohenga matū, me te ariā o ngā mole. Mā te whakaharatau ki ngā tauira raruraru maha ka āwhina i te whakapakari i te māramatanga ki te whanaungatanga i waenga i ngā matū tauhohenga me ngā hua i roto i ngā tauhohenga matū. Kei roto i tēnei tuhinga ētahi tauira raruraru e kapi ana i ngā momo tauhohenga, mai i ngā mea māmā ki ngā mea e pā ana ki ngā matū tauhohenga whakawhāiti, hei āwhina i te whakamārama i te ariā o te stoichiometry.
