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

[medaspirant]

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?

 

[LennonTheLemon]

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]

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