Classifying salts as acidic, basic, or neutral
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Classifying salts as acidic, basic, or neutral
Hi, I'm super confused on how to classify salts based on whether they are acidic, basic, or neutral? I looked it up and it said to add H+ to the anion and OH- to the cation and see if they are on the list of strong acids/strong bases, but is there another way to classify the salts? For example, like in the sapling homework, how would you classify NH4Br, K2SO3, Na2S, KCl, and LiBr?
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Re: Classifying salts as acidic, basic, or neutral
LiNO3 and KCl contain cations/anions from strong acids/bases. Because they contain elements of both strong bases and strong acids, these compounds are neutral.
K2CO3 and NaCN contain the cation of a strong base and an anion from a weak acid. A weak acid has a strong conjugate base, so these compounds will be basic.
NH4Br contains the anion of a strong acid and a cation from a weak base. A weak base has a strong conjugate acid, so this compound will be acidic.
K2CO3 and NaCN contain the cation of a strong base and an anion from a weak acid. A weak acid has a strong conjugate base, so these compounds will be basic.
NH4Br contains the anion of a strong acid and a cation from a weak base. A weak base has a strong conjugate acid, so this compound will be acidic.
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Re: Classifying salts as acidic, basic, or neutral
What I do and have learned from TA sessions is to separate the salt into their conjugate bases or acids. Take LiBr for example. We separate them to Li+ (conjugate acid) and Br-(conjugate base.) Looking at the charges we look at which of them likes a positive H ion or a negative OH ion. From there we determine which is strong and weak. So, we get LiOH and HBr. We know that HBr is a strong acid and LiOH(being a Group 1 hydroxide) is a strong base. A strong base and a strong acid create neutral salt. A weak acid and a strong base create a basic salt. A strong acid and a weak base form an acidic salt. Hope this helps!
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Re: Classifying salts as acidic, basic, or neutral
i was struggling w this concept too. the rule that I've been following is that if a given element is associate with a strong base or a strong acid, it will not affect the pH of the solution. NaCl for example: Na is associated w NaOH and Cl is associated w HCl. if you were to mix Na or Cl with water separately, there would not be an increase in either H+ or OH- so the salt is neutral.
on the other hand, if you were trying to classify KF, it would be basic. so you "eliminate" the K+ from the equation bc it is associated w strong base KOH. then you could write out the equation if you added the remaining F- to water. an H from the water would go to the F-, creating an excess of OH=, so that salt would be considered basic. i hope that makes sense it's hard to explain without visuals.
idk if it's posted on chem community but michael''s review on acids and bases was SUPER helpful and he explained this super well
on the other hand, if you were trying to classify KF, it would be basic. so you "eliminate" the K+ from the equation bc it is associated w strong base KOH. then you could write out the equation if you added the remaining F- to water. an H from the water would go to the F-, creating an excess of OH=, so that salt would be considered basic. i hope that makes sense it's hard to explain without visuals.
idk if it's posted on chem community but michael''s review on acids and bases was SUPER helpful and he explained this super well
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