Ngā Tauira Pātai me te Kōrero mō te Whakamāramatanga o te Stoichiometry
Ko te Stoichiometry he peka o te matū e ako ana i ngā rahinga o ngā matū e uru ana ki ngā tauhohenga matū. Ko te kupu 'stoichiometry' i ahu mai i ngā kupu Kariki "stoicheion," ko tōna tikanga he huānga, me te "metron," ko tōna tikanga he ine. Ko te Stoichiometry e aro ana ki te ōwehenga o ngā mole, te papatipu, te rōrahi, me ngā matūriki i roto i te tauhohenga matū. He mea nui te Stoichiometry i roto i te matū nā te mea ka whakaratohia te pūtake mō te tātari tauhohenga, ā, ka āwhina i ngā kaipūtaiao ki te whakatau i te nui o ngā matū e hiahiatia ana, e whakaputaina ana rānei i roto i te tauhohenga matū.
Hei mārama ake i te ariā o te stoichiometry, me matapaki tātou i ētahi tauira pātai me ō rātou matapakinga.
Ngā Tauira Pātai Stoikiometry
Pātai 1: Ngā tauhohenga matū māmā
Whakaarohia te tauhohenga e whai ake nei:
\[ \text{H}_2 + \text{O}_2 \rightarrow \text{H}_2\text{O} \]
Ki te tīmata tātou me ngā ira H₂ e 4 me ngā ira O₂ e 4, e hia ngā ira H₂O ka puta? Ka pau katoa ngā matū tauhohe, ka toe rānei ētahi atu?
Kōrero:
Ko te taahiraa tuatahi ko te tuhi i tētahi whārite matū taurite:
\[ \text{2H}_2 + \text{O}_2 \rightarrow \text{2H}_2\text{O} \]
E whakaatu ana tēnei whārite e 2 ngā mole o te H₂ e tauhohe ana ki te 1 mole o te O₂ hei whakaputa i te 2 ngā mole o te H₂O. Mai i tēnei, ka kitea te maha o ngā mole o te H₂O i hangaia mā te whakamahi i te stoichiometry.
1. Tātaihia ngā mole o te taikaha me te paunga:
Mō ia 2 ira o te H₂, e hiahiatia ana kia 1 ira o te O₂. Ka tīmata tātou me ngā ira e 4 o te H₂ me ngā ira e 4 o te O₂.
– e hiahiatia ana \( \frac{4 \text{ mol H₂}}{2} = 2 \text{ mol O₂} \).
– Nā te mea e 4 ngā mole o te O₂, ko te O₂ te matū e toe ana.
2. Tātaihia te maha o ngā hua:
Waihoki, ka puta te maha o ngā mole o te H₂ e 4 ngā mole o te H₂O, nā te mea ko ia 2 mole o te H₂ e tauhohe ana ka puta te 2 mole o te H₂O.
\[ 4\kākau{ mol H₂} \times \frac{2 \kākau{ mol H}_2\kākau{O}}{2 \kākau{ mol H}_2} = 4 \kākau{ mol H}_2\kākau{O} \]
Nō reira, ka hangaia he 4 mole wai, ā, kāore e whakamahia te toenga O₂.
Pātai 2: Tauhohenga Mura
Ka tahuna te Benzene (C₆H₆) ki te hāora hei whakaputa i te hauhā me te wai penei:
\[ 2\kuputuhi{ C}_6\kuputuhi{H}_6 + 15\kuputuhi{ O}_2 \rightarrow 12\kuputuhi{ CO}_2 + 6\kuputuhi{ H}_2\kuputuhi{O} \]
Ki te tahuna te 1 mole o te C₆H₆, e hia ngā mole o te CO₂ me te H₂O ka puta? E hia ngā mole o te O₂ e hiahiatia ana?
Kōrero:
Whakamahia te whārite stoichiometric i runga ake nei hei whakaoti i te raruraru:
1. Tātaihia ngā mole o te CO₂ me te H₂O i hangaia:
\[ \kuputuhi{C}_6\kuputuhi{H}_6 \]
\[ 1 \text{ mol C}_6\text{H}_6 \text{ he ōrite ki } 12 \text{ mol CO}_2 (mō te 2 mol C}_6\text{H}_6) \]
Mai i te ōwehenga stoichiometric:
\[ 1 \text{ mol C}_6\text{H}_6 = \frac{12 \text{ mol CO}_2}{2} \]
\[ = 6 \text{ mol CO}_2 \]
Waihoki mō H₂O:
\[ 1 \text{ mol C}_6\text{H}_6 = \frac{6 \text{ mol H}_2\text{O}}{2} \]
\[ = 3 \text{ mol H}_2\text{O} \]
2. Tāutuhia ngā mole o te O₂ e hiahiatia ana:
\[ 1 \text{ mol C}_6\text{H}_6 = \frac{15 \text{ mol O}_2}{2} \]
\[ = 7.5 \text{ mol O}_2 \]
Pātai 3: Ngā Tauhohenga Whakakore Waikawa-Pūtake
E hia rita o te hau CO₂ ka puta (i raro i ngā tikanga paerewa) ina tauhohehia te 5 karamu o te konutai kāponāte (Na₂CO₃) ki te waikawa hauwai nui rawa, e ai ki te tauhohenga:
\[ \kuputuhi{Na}_2\kuputuhi{CO}_3 + 2\kuputuhi{HCl} \rightarrow 2\kuputuhi{NaCl} + \kuputuhi{H}_2\kuputuhi{O} + \kuputuhi{CO}_2 \]
Kōrero:
1. Tātaihia ngā mole o te Na₂CO₃:
Papatipu molar o Na₂CO₃:
\[ (2 \times 23) + 12 + (3 \times 16) = 106 \text{ g/mol} \]
Ngā ira o te Na₂CO₃ e wātea ana:
\[ \frac{5 \text{ g Na₂CO₃}}{106 \text{ g/mol}} = 0.047 \text{ mol Na₂CO₃} \]
2. E hia ngā mole o te CO₂ ka hangaia:
\[ 1 \text{ mol Na₂CO₃} ka whakaputa 1 \text{ mol CO}_2 \]
Nō reira, ka puta mai i te 0.047 mol o te Na₂CO₃:
\[ 0.047 \text{ mol CO}_2 \]
I raro i ngā tikanga paerewa (STP: 22.4 L/mol):
\[ 0.047 \kuputuhi{ mol } \times 22.4 \kuputuhi{ L/mol} = 1.05 \kuputuhi{ L CO}_2 \]
Whakamutunga
Mai i te tauira raruraru i runga ake nei, ka kite tātou he maha ngā mahi nui o te stoichiometry: te huri i te papatipu ki ngā mole, te whakamahi i ngā ōwehenga molar mai i ngā whārite taurite, ā, hei whakamutunga, te huri anō ki ngā waeine e hiahiatia ana. He mea nui te mārama ki te stoichiometry mō te angitu ki te tātari i ngā tauhohenga matū me te whakamahere i ngā hanganga matū. Mā te mahi tonu, ka noho te stoichiometry hei taputapu tino whai hua i roto i te ao matū.
