Chitsanzo cha Funso Lokambirana pa Bond Energy
Pendauluan
Mphamvu ya bond ndi lingaliro lofunika kwambiri mu chemistry lomwe limatithandiza kumvetsetsa mphamvu yofunikira kuti tiswe mgwirizano mkati mwa molekyulu. Mwachidule, mphamvu ya bond ndi kuchuluka kwa mphamvu yofunikira kuti tilekanitse maatomu awiri omangika pamodzi mu molekyulu kukhala maatomu osiyana. M'nkhaniyi, timvetsetsa lingaliro la mphamvu ya bond kudzera mu zitsanzo zingapo za mavuto ndi kukambirana kwawo.
Lingaliro la Mphamvu Yogwirizanitsa
Mphamvu ya bond imafotokozedwa mu ma kilojoules pa mole (kJ/mol), ndipo mtundu uliwonse wa bond ya mankhwala uli ndi mphamvu yosiyana ya bond. Mwachitsanzo, mphamvu ya bond ya bond imodzi ya C-H (carbon-hydrogen) ndi yosiyana ndi mphamvu ya bond ya bond iwiri ya C=O (carbon-oxygen).
Equation yomwe imagwiritsidwa ntchito kwambiri powerengera kusintha kwa enthalpy kwa reaction (\(\Delta H\)) poganizira mphamvu za bond ndi:
\[
\Delta H = \Sigma D_{\text{reactants}} – \Sigma D_{\text{products}}
\]
Kumene \(D_{\text{reactants}}\) ndi \(D_{\text{products}}\) ndi mphamvu zomangira zomwe zimakhudzidwa ndi zinthu zomangira ndi zinthu. Mwa kuyankhula kwina, kuchuluka kwa mphamvu zomangira mu zinthu zomangira kuchotsa kuchuluka kwa mphamvu zomangira mu zinthuzo.
Mafunso ndi Kukambirana Zitsanzo
Funso 1
Amadziwika kuti mphamvu yapakati ya ma bond pa ma bond otsatirawa ndi:
– HH bond: 436 kJ/mol
– O=O chigwirizano: 498 kJ/mol
– HO bond: 463 kJ/mol
Werengani kusintha kwa enthalpy (\(\Delta H\)) pa zomwe zachitika:
\[
2H_2(g) + O_2(g) \kumanja 2H_2O(g)
\]
Kukambirana:
Gawo loyamba ndi kulemba zomwe zimachitika ndikuwerengera kuchuluka kwa ma bond omwe alipo mu reactants ndi zinthu.
Kwa ma reactants:
– Mamolekyu awiri a \(H_2\) amatanthauza kuti pali ma HH bond awiri
– Molekyu imodzi ya \(O_2\) imatanthauza kuti pali 1 O=O bond
Za zinthu:
– 2 \(H_2O\) mamolekyu amatanthauza 4 H2O bonds
Mphamvu yonse yolumikizirana mu reactants:
\[
2 \nthawi \malemba{Mphamvu ya Bond HH} + 1 \nthawi \malemba{Mphamvu ya Bond O=O}
\]
\[
= 2 \nthawi 436 + 1 \nthawi 498
\]
\[
= 872 + 498
\]
\[
= 1370 \malemba{kJ/mol}
\]
Mphamvu yonse ya bond mu chinthucho:
\[
4 \nthawi \zolemba{HO mphamvu yolumikizirana}
\]
\[
= 4 \nthawi 463
\]
\[
= 1852 \malemba{kJ/mol}
\]
Kusintha kwa Enthalpy (\(\Delta H\)):
\[
\Delta H = \Sigma D_{\text{reactants}} – \Sigma D_{\text{products}}
\]
\[
= 1370 \mawu{kJ/mol} – 1852 \mawu{kJ/mol}
\]
\[
= -482 \malemba{ kJ/mol}
\]
Kotero, kusintha kwa enthalpy kwa reaction ndi \(-482\) kJ/mol.
Funso 2
Akuti mphamvu zotsatirazi za ma bond zimadziwika:
– CH bond: 414 kJ/mol
– C=C bond: 612 kJ/mol
– HH bond: 436 kJ/mol
Werengani kusintha kwa enthalpy (\(\Delta H\)) pa zomwe zachitika:
\[
C_2H_4(g) + H_2(g) \muvi wa kumanja C_2H_6(g)
\]
Kukambirana:
Gawo loyamba ndi kulemba zomwe zimachitika ndikuwerengera kuchuluka kwa ma bond omwe alipo mu reactants ndi zinthu.
Kwa ma reactants:
– Molekyu imodzi ya \(C_2H_4\) (ethylene) ili ndi ma bond 4 CH ndi bond 1 C=C
– Molekyu imodzi ya \(H_2\) ili ndi chigwirizano chimodzi cha HH
Za zinthu:
– Molekyu imodzi ya \(C_2H_6\) (ethane) ili ndi ma bond 6 CH ndi bond 1 CC
Mphamvu yonse yolumikizirana mu reactants:
\[
4 \nthawi \malemba{Mphamvu ya Bond CH} + 1 \nthawi \malemba{Mphamvu ya Bond C=C} + 1 \nthawi \malemba{Mphamvu ya Bond HH}
\]
\[
= 4 \nthawi 414 + 1 \nthawi 612 + 1 \nthawi 436
\]
\[
= 1656 + 612 + 436
\]
\[
= 2704 \malemba{kJ/mol}
\]
Mphamvu yonse ya bond mu chinthucho:
\[
6 \nthawi \malemba{CH mphamvu yolumikizirana} + 1 \nthawi \malemba{CC mphamvu yolumikizirana}
\]
\[
= 6 \nthawi 414 + 1 \nthawi 348
\]
\[
= 2484 + 348
\]
\[
= 2832 \malemba{kJ/mol}
\]
Kusintha kwa Enthalpy (\(\Delta H\)):
\[
\Delta H = \Sigma D_{\text{reactants}} – \Sigma D_{\text{products}}
\]
\[
= 2704 \mawu{kJ/mol} – 2832 \mawu{kJ/mol}
\]
\[
= -128 \malemba{ kJ/mol}
\]
Kotero, kusintha kwa enthalpy kwa reaction ndi \(-128\) kJ/mol.
Mapeto
Lingaliro la mphamvu yomangirira ndi chinthu chofunikira kwambiri pophunzira momwe mankhwala amachitira ndi kusintha kwa enthalpy. M'nkhaniyi, takambirana zitsanzo ziwiri za mavuto omwe akuwonetsa momwe tingawerengere kusintha kwa enthalpy pazochitika pogwiritsa ntchito mphamvu yomangirira. Kumvetsetsa kumeneku ndikofunikira kwambiri pakugwiritsa ntchito mankhwala osiyanasiyana, kuyambira kupanga zinthu zachilengedwe mpaka kupanga mafuta. Kumvetsetsa kwakuya kungapezeke mwa kuchita nthawi zonse komanso kufufuza mitundu yosiyanasiyana ya machitidwe a mankhwala.
Chonde gwiritsani ntchito njira zomwe zafotokozedwa m'nkhaniyi ngati chitsogozo chothetsera mavuto amtsogolo a mphamvu ya ma bond, ndipo ganizirani zinthu zina zowonjezera zophunzirira kuti muwonjezere chidziwitso chanu cha chemistry ya mphamvu ya ma bond.
