Acid, base or neutral
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Acid, base or neutral
How do we tell what is an acid/base/neutral outside of the ones that we had to memorize?
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Re: Acid, base or neutral
Basically I think you would have to see if it produces H+ or OH- ions when it is in water. Not really sure how to tell if it is neutral though.
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Re: Acid, base or neutral
Hi! We can analyze the molecule we are given by determining whether their ions come from strong/weak acids or bases. In particular, if the cation is from a corresponding weak base but the anion is from a strong acid, this salt will have acidic character. Conversely, if the cation is from a strong base but the anion is from a weak acid, the salt will have basic character. Finally, if the cation is from a strong base and the anion is also form a strong acid, the salt will be neutral. Hope this helps!
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Re: Acid, base or neutral
Hi, something else I like to consider is that acids typically have a hydrogen at the beginning of their chemical formula; for example HCl, HBr, or HNO3. Additionally, acids also can have a COOH at the end like CH3COOH.
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Re: Acid, base or neutral
Just to add on, molecules with a nitrogen that has a long pair is a base. You can analyze the Lewis structure of each molecule to see if it is likely to accept or donate electrons. Also, a couple tables in the textbook are pretty useful, such as 6D.1 and 6D.2.
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Re: Acid, base or neutral
Strong Acids:
- Many inorganic acids are strong
- Strong acids have high Ka and small pKa values
Examples: HCl, HNO3, H2SO4
Weak Acids:
- Many organic acids are weak.
- Weak acids have very small Ka values and large pKa values
Examples: HO2C2O2H, H2SO3, HSO4-
Strong Bases:
- Many strong bases are metal hydroxides and metal oxides
- Strong bases have high Kb and small pKb values
Examples: LiOH, NaOH, Li2O
Weak Bases:
- Many weak bases have a N atom with a lone pair.
- Weak bases have very small Kb values and large pKb values
Examples: NH3, CH3NH2, C5H5N
- Many inorganic acids are strong
- Strong acids have high Ka and small pKa values
Examples: HCl, HNO3, H2SO4
Weak Acids:
- Many organic acids are weak.
- Weak acids have very small Ka values and large pKa values
Examples: HO2C2O2H, H2SO3, HSO4-
Strong Bases:
- Many strong bases are metal hydroxides and metal oxides
- Strong bases have high Kb and small pKb values
Examples: LiOH, NaOH, Li2O
Weak Bases:
- Many weak bases have a N atom with a lone pair.
- Weak bases have very small Kb values and large pKb values
Examples: NH3, CH3NH2, C5H5N
Re: Acid, base or neutral
To determine if a substance is an acid, base, or neutral, you typically look at its ability to donate or accept hydrogen ions (H+) in water, or refer to its pH value, with acids having pH less than 7, bases having pH greater than 7, and neutral substances having a pH of 7.
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