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acid and bases
- Thread starter dying2badentist
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dying2badentist said:
anyone?
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Arrhenius: acid is a substance that donate H+. HCl, H2SO4
Arrhenius: base is a substance that donates OH-. KOH and Ca(OH)2
Bronsted-Lowry: acid donates H+ to others. HCl, H2SO4
Bronsted-Lowry: base accept H+ from others
Lewis: accepts pair electron.,BF3
Lewis: donates pair electron, :NH3
When you compare these definitions you will see that acids have electron deficiency, but bases have electron surplus.
Acids are hungry for electron. Since they want to keep pair electron shared between them and H+, they want to get ride of H+. So they kick H+ out. If a substance want to give them pair electron, they say WE ACCEPT, thank you. If you think of electrons as money, you can imagine that Lewis acid is a needy with no pride and bronsted-Lowry acid is a cold blooded person that sacrifice a member of a family(H+) just to put hands on more accets. So clear-cut definition for acid is GREED.
Bases are blessed with electron. These substances not only have enough electrons for themselves, they are donate electrons in a generous way. According to Arrhenius, they sent out a proton with not only an O but with an extra pair of electrons (OH-). According to Bronsted-Lowry they accept poor frighten member of greedy acides (H+). According to Lewis they donate pair electron to the other substances. So clear-cut definition for bases is GENEROUSITY.
Hope this help
Arrhenius: base is a substance that donates OH-. KOH and Ca(OH)2
Bronsted-Lowry: acid donates H+ to others. HCl, H2SO4
Bronsted-Lowry: base accept H+ from others
Lewis: accepts pair electron.,BF3
Lewis: donates pair electron, :NH3
When you compare these definitions you will see that acids have electron deficiency, but bases have electron surplus.
Acids are hungry for electron. Since they want to keep pair electron shared between them and H+, they want to get ride of H+. So they kick H+ out. If a substance want to give them pair electron, they say WE ACCEPT, thank you. If you think of electrons as money, you can imagine that Lewis acid is a needy with no pride and bronsted-Lowry acid is a cold blooded person that sacrifice a member of a family(H+) just to put hands on more accets. So clear-cut definition for acid is GREED.
Bases are blessed with electron. These substances not only have enough electrons for themselves, they are donate electrons in a generous way. According to Arrhenius, they sent out a proton with not only an O but with an extra pair of electrons (OH-). According to Bronsted-Lowry they accept poor frighten member of greedy acides (H+). According to Lewis they donate pair electron to the other substances. So clear-cut definition for bases is GENEROUSITY.
Hope this help
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desert said:Arrhenius: acid is a substance that donate H+. HCl, H2SO4
Arrhenius: base is a substance that donates OH-. KOH and Ca(OH)2
Bronsted-Lowry: acid donates H+ to others. HCl, H2SO4
Bronsted-Lowry: base accept H+ from others
Lewis: accepts pair electron.,BF3
Lewis: donates pair electron, :NH3
When you compare these definitions you will see that acids have electron deficiency, but bases have electron surplus.
Acids are hungry for electron. Since they want to keep pair electron shared between them and H+, they want to get ride of H+. So they kick H+ out. If a substance want to give them pair electron, they say WE ACCEPT, thank you. If you think of electrons as money, you can imagine that Lewis acid is a needy with no pride and bronsted-Lowry acid is a cold blooded person that sacrifice a member of a family(H+) just to put hands on more accets. So clear-cut definition for acid is GREED.
Bases are blessed with electron. These substances not only have enough electrons for themselves, they are donate electrons in a generous way. According to Arrhenius, they sent out a proton with not only an O but with an extra pair of electrons (OH-). According to Bronsted-Lowry they accept poor frighten member of greedy acides (H+). According to Lewis they donate pair electron to the other substances. So clear-cut definition for bases is GENEROUSITY.
Hope this help
Yeh that helps. But when you see the question on the exam..."Which is the best Acid"...what is the best way to go about solving for that? (as well as questions for bases)
Thanks in advance!
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clemsontigers said:
I have never seen a question asked in that manner. Can you elaborate a little? "What is the srongest acid?"...what do you mean by best?
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lifeisgood said:
best looking~ 😀
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Always refer to the fundomental definition and think about electron flow.
For acids, use your feeling to see which one may has H+, act greedier to give up H+ and keeping the electron pair or willing to accept pair electron. Remember that acids are greedy.
For the bases look which one has OH-, accepts H+ or willing to donate pair electron. Remember that bases are generous.
In HCLO4 ,HCLO3 ,HCLO2 ,HCLO b/c of high number of electronegative O in HCLO4, central atom in this molecule is more willing to kick off H+ and keep the electron pair. So this need makes the molecule greedy and stronger acid.
In ph-COOH ,CH3O-ph-COOH b/c methoxy group donate electron (generous group)to the ring, the molecule is not needy, so CH3O-ph-COOH is weak acid and shows basicity (or better base)
CH3NH3+ , CH3NH2 b/c CH3NH3+ has + charge it is needy to get pair electron ,so it is stronger acid. You may say it has more H to kick off.
CH3OH, CH3NH2 b/c O is more electronegative than N, CH3OH is more greedy, so stronger acid.
I hope this clarify how this student definition works in the exam
For acids, use your feeling to see which one may has H+, act greedier to give up H+ and keeping the electron pair or willing to accept pair electron. Remember that acids are greedy.
For the bases look which one has OH-, accepts H+ or willing to donate pair electron. Remember that bases are generous.
In HCLO4 ,HCLO3 ,HCLO2 ,HCLO b/c of high number of electronegative O in HCLO4, central atom in this molecule is more willing to kick off H+ and keep the electron pair. So this need makes the molecule greedy and stronger acid.
In ph-COOH ,CH3O-ph-COOH b/c methoxy group donate electron (generous group)to the ring, the molecule is not needy, so CH3O-ph-COOH is weak acid and shows basicity (or better base)
CH3NH3+ , CH3NH2 b/c CH3NH3+ has + charge it is needy to get pair electron ,so it is stronger acid. You may say it has more H to kick off.
CH3OH, CH3NH2 b/c O is more electronegative than N, CH3OH is more greedy, so stronger acid.
I hope this clarify how this student definition works in the exam
