1. Mg + CuSO4 —> MgSO4 + Cu
=> Single displacement reaction 
2. 2HCI + Mg(OH)2 —> MgCI2 + H2O
=> Acid - base reaction 
3.AgNO3 + NaCI —> AgCI + NaNO3
=> Double displacement reaction
 
        
             
        
        
        
To identify minerals
Each material chemical makeup are a variety of chemical compounds which has each own category. They have different functional groups which helps people identify which material they look for. For instance, hydroxyl group has chemical makeup of alcohol
 
        
                    
             
        
        
        
The balanced equation for the reaction is ;
2Zn + O2 —> 2ZnO
The stoichiometry of O2 to ZnO is 1:2
The mass of ZnO formed - 358.5 g
The number of moles formed - 358.5 g / 81.4 g/mol = 4.4 moles 
Therefore number of O2 moles reacted = 4.4 moles /2 = 2.2 mol
Mass of O2 reacted = 2.2 mol x 32 g/mol = 70.4 g
        
             
        
        
        
This allows us to visually see the structure of the atoms/ molecules so we can get a better understanding of what they look like.