@CausticSyndicalist
Which describes a process where a precipitate is formed?

A.
A solution of AgNO3 is added to a solution of CaCl2 to produce solid AgCl and a solution of CaNO3.

B.
Propane gas combusts to form CO2 and H2O.

C.
A solution of HCl mixes with a solution of Ca(OH)2 to produce H2O and CaCl2.

D.
A solution of H2SO4 mixes with a solution of NaOH to produce water and Na2SO4.

Question

@CausticSyndicalist
 Which describes a process where a precipitate is formed?  
 
 

 
 

  

  A.  
A solution of AgNO3 is added to a solution of CaCl2 to produce solid AgCl and a solution of CaNO3.
   
   

 
 

  

  B.  
Propane gas combusts to form CO2 and H2O.
   
   

 
 

  

  C.  
A solution of HCl mixes with a solution of Ca(OH)2 to produce H2O and CaCl2.
   
   

 
 

  

  D. 
A solution of H2SO4 mixes with a solution of NaOH to produce water and Na2SO4.

causticsyndicalist · Answer

A precipitation reaction is used to make an insoluble salt. Two solutions with the needed ions are reacted together to form the wanted insoluble salt. For example, to form lead chloride, a solution with lead (eg. Lead nitrate solution as most nitrates are soluble) and sodium chloride solution (as all group 1 solids are soluble) are mixed, to form sodium nitrate and lead chloride.
So it would be A.