---
title: "Amphoterism"
chunk: 2/2
source: "https://en.wikipedia.org/wiki/Amphoterism"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T10:51:47.144736+00:00"
instance: "kb-cron"
---

  
    
      
        
          
            SnO
            
              2
            
            
              
            
          
          +
          
            
              
                4
                
                HCl
              
              acid
            
          
          
            
              
                
                  
                    
                      ↽
                    
                    
                    
                    
                      −
                    
                  
                
              
              
                
                  
                    
                      −
                    
                    
                    
                    
                      ⇀
                    
                  
                
              
            
          
          
            SnCl
            
              4
            
            
              
            
          
          +
          2
          
          
            H
            
              2
            
            
              
            
          
          O
        
      
    
    {\displaystyle {\ce {SnO2 + {\overset {acid}{4 HCl}}<=> SnCl4 + 2H2O}}}
  

  
    
      
        
          
            SnO
            
              2
            
            
              
            
          
          +
          
            
              
                4
                
                NaOH
              
              base
            
          
          +
          2
          
          
            H
            
              2
            
            
              
            
          
          O
          
            
              
                
                  
                    
                      ↽
                    
                    
                    
                    
                      −
                    
                  
                
              
              
                
                  
                    
                      −
                    
                    
                    
                    
                      ⇀
                    
                  
                
              
            
          
          
            Na
            
              4
            
            
              
            
          
          
            [
            Sn
            
              
                (
                OH
                )
              
              
                8
              
              
                
              
            
            ]
          
        
      
    
    {\displaystyle {\ce {SnO2 + {\overset {base}{4 NaOH}}+ 2H2O <=> Na4[Sn(OH)8]}}}
  

Vanadium dioxide (VO2):

  
    
      
        
          
            VO
            
              2
            
            
              
            
          
          +
          
            
              
                2
                
                HCl
              
              acid
            
          
          ⟶
          
            VOCl
            
              2
            
            
              
            
          
          +
          
            H
            
              2
            
            
              
            
          
          O
        
      
    
    {\displaystyle {\ce {VO2 + {\overset {acid}{2 HCl}}-> VOCl2 + H2O}}}
  

  
    
      
        
          4
          
          
            VO
            
              2
            
            
              
            
          
          +
          
            
              
                2
                
                NaOH
              
              base
            
          
          ⟶
          
            Na
            
              2
            
            
              
            
          
          
            V
            
              4
            
            
              
            
          
          
            O
            
              9
            
            
              
            
          
          +
          
            H
            
              2
            
            
              
            
          
          O
        
      
    
    {\displaystyle {\ce {4 VO2 + {\overset {base}{2 NaOH}}-> Na2V4O9 + H2O}}}
  

Some other elements which form amphoteric oxides are gallium, indium, scandium, titanium, zirconium, chromium, iron, cobalt, copper, silver, gold, germanium, antimony, bismuth, beryllium, and tellurium.

== Hydroxides ==
Aluminium hydroxide is also amphoteric:

  
    
      
        
          Al
          
            
              (
              OH
              )
            
            
              3
            
            
              
            
          
          +
          
            
              
                3
                
                HCl
              
              acid
            
          
          ⟶
          
            AlCl
            
              3
            
            
              
            
          
          +
          3
          
          
            H
            
              2
            
            
              
            
          
          O
        
      
    
    {\displaystyle {\ce {Al(OH)3 + {\overset {acid}{3 HCl}}-> AlCl3 + 3 H2O}}}
  

  
    
      
        
          Al
          
            
              (
              OH
              )
            
            
              3
            
            
              
            
          
          +
          
            
              NaOH
              base
            
          
          ⟶
          Na
          
            [
            Al
            
              
                (
                OH
                )
              
              
                4
              
              
                
              
            
            ]
          
        
      
    
    {\displaystyle {\ce {Al(OH)3 + {\overset {base}{NaOH}}-> Na[Al(OH)4]}}}
  

Beryllium hydroxide:

  
    
      
        
          Be
          
            
              (
              OH
              )
            
            
              2
            
            
              
            
          
          +
          
            
              
                2
                
                HCl
              
              acid
            
          
          ⟶
          
            BeCl
            
              2
            
            
              
            
          
          +
          2
          
          
            H
            
              2
            
            
              
            
          
          O
        
      
    
    {\displaystyle {\ce {Be(OH)2 + {\overset {acid}{2 HCl}}-> BeCl2 + 2 H2O}}}
  

  
    
      
        
          Be
          
            
              (
              OH
              )
            
            
              2
            
            
              
            
          
          +
          
            
              
                2
                
                NaOH
              
              base
            
          
          ⟶
          
            Na
            
              2
            
            
              
            
          
          
            [
            Be
            
              
                (
                OH
                )
              
              
                4
              
              
                
              
            
            ]
          
        
      
    
    {\displaystyle {\ce {Be(OH)2 + {\overset {base}{2 NaOH}}-> Na2[Be(OH)4]}}}
  

Chromium hydroxide:

  
    
      
        
          Cr
          
            
              (
              OH
              )
            
            
              3
            
            
              
            
          
          +
          
            
              
                3
                
                HCl
              
              acid
            
          
          ⟶
          
            CrCl
            
              3
            
            
              
            
          
          +
          3
          
          
            H
            
              2
            
            
              
            
          
          O
        
      
    
    {\displaystyle {\ce {Cr(OH)3 + {\overset {acid}{3 HCl}}-> CrCl3 + 3H2O}}}
  

  
    
      
        
          Cr
          
            
              (
              OH
              )
            
            
              3
            
            
              
            
          
          +
          
            
              NaOH
              base
            
          
          ⟶
          Na
          
            [
            Cr
            
              
                (
                OH
                )
              
              
                4
              
              
                
              
            
            ]
          
        
      
    
    {\displaystyle {\ce {Cr(OH)3 + {\overset {base}{NaOH}}-> Na[Cr(OH)4]}}}
  

== See also ==

Ate complex
Isoelectric point
Zwitterion

== References ==