TBR Gen Chem Passage II Chapter 4 (acid and bases)

[jsmith1]

Question 8 says that in Trial 5 and 6 both KOH and KOAc completely dissociate in water but question 9 says HF will not dissociate as much as HCl in water because HF is a weak acid. I get the HF part but ist KOAc a weak acid and KOH a strong acid? So wont KOAc also not fully dissociate in water?

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[QrtrLifeCrisis]

Question 8 says that in Trial 5 and 6 both KOH and KOAc completely dissociate in water but question 9 says HF will not dissociate as much as HCl in water because HF is a weak acid. I get the HF part but ist KOAc a weak acid and KOH a strong acid? So wont KOAc also not fully dissociate in water?

KOAc and KOH are both BASES. There's no dissociating of H+ going on here. K+ just comes off leaving the negatively charged bases, OAc and OH.

 

[grburst]

Question 8 says that in Trial 5 and 6 both KOH and KOAc completely dissociate in water but question 9 says HF will not dissociate as much as HCl in water because HF is a weak acid. I get the HF part but ist KOAc a weak acid and KOH a strong acid? So wont KOAc also not fully dissociate in water?

KOAc and KOH are potassium salts, which are always soluble in water. The cation and anion of each compound will separate (solvation energy > lattice energy), and the partially-negative oxygen's of H2O orient around the the K+ cation and the partially-positive H's of H2O will orient around the negatively-charged oxygen of either -OAc or -OH anions.

 

[jsmith1]

KOAc and KOH are both BASES. There's no dissociating of H+ going on here. K+ just comes off leaving the negatively charged bases, OAc and OH.

Yea sorry typo..I meant to say bases. So even though KOAc is a WEAK base it will still fully dissociate in water?

 

[QrtrLifeCrisis]

Yea sorry typo..I meant to say bases. So even though KOAc is a WEAK base it will still fully dissociate in water?

Yep, mainly because of what the other poster said: K+ salts dissociate completely.