q on amphiprotic substances and writing eqs to show (1 Viewer)

medaspirant

Member
Joined
Oct 18, 2021
Messages
51
Gender
Male
HSC
2022
hi if someone could explain what reagents to use when proving / showing a substance is amphiprotic. is hydronium ions to prove its basic, and hydroxide to prove its acidic good?
 
Joined
Mar 30, 2020
Messages
67
Gender
Male
HSC
2021
Yeah, my favourite amphiprotic substance is actually water. You can take water and put it into an acidic or basic environment.

If you react to water with H3O+ which is more acidic, then water will act as a base and accept a proton from hydronium. However, this also links to the auto-ionisation of water If I remember correctly.

In acidic environments, I just use whatever strong acid I feel like. For example:
HCl (aq) + H2O (l) ⇌ H3O+ (aq) + Cl- (aq)
Since HCl is more acidic, water must act as a base and accept a proton, thus countering the release of H+ and why you can run water over your skin if you get acid on yourself. In a lab, it's best to use a powdered substance like sodium bicarbonate (NaHCO3) so that you don't make the acid spill larger and messier.
H3O+ (aq) + HCO3- (aq) ⇌ H2CO3 (aq) + H2O (l) [this is the NaHCO3 reaction I was referring to]

In basic environments, I just use whatever base comes to mind (right now I literally just thought of ammonia so yeet):
NH3 (aq) + H2O (l) ⇌ OH- (aq) + NH4+ (aq)
Since NH3 is more basic, water must act as an acid and donate a proton to it, so the water becomes OH- and NH3 accepts a proton to become an ammonium cation.
OH- (aq) + HCO3- (aq) ⇌ CO3^2- (aq) + H2O (l) [once again why NaHCO3 can be used for base spills as well]
 

medaspirant

Member
Joined
Oct 18, 2021
Messages
51
Gender
Male
HSC
2022
Yeah, my favourite amphiprotic substance is actually water. You can take water and put it into an acidic or basic environment.

If you react to water with H3O+ which is more acidic, then water will act as a base and accept a proton from hydronium. However, this also links to the auto-ionisation of water If I remember correctly.

In acidic environments, I just use whatever strong acid I feel like. For example:
HCl (aq) + H2O (l) ⇌ H3O+ (aq) + Cl- (aq)
Since HCl is more acidic, water must act as a base and accept a proton, thus countering the release of H+ and why you can run water over your skin if you get acid on yourself. In a lab, it's best to use a powdered substance like sodium bicarbonate (NaHCO3) so that you don't make the acid spill larger and messier.
H3O+ (aq) + HCO3- (aq) ⇌ H2CO3 (aq) + H2O (l) [this is the NaHCO3 reaction I was referring to]

In basic environments, I just use whatever base comes to mind (right now I literally just thought of ammonia so yeet):
NH3 (aq) + H2O (l) ⇌ OH- (aq) + NH4+ (aq)
Since NH3 is more basic, water must act as an acid and donate a proton to it, so the water becomes OH- and NH3 accepts a proton to become an ammonium cation.
OH- (aq) + HCO3- (aq) ⇌ CO3^2- (aq) + H2O (l) [once again why NaHCO3 can be used for base spills as well]
ah ok thanks, your detailed answer helps so much thx
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top