What is the arrhenius definition of an acid? a substance that increases h3o+ concentration when it is dissolved in water. a substance that increases oh– concentration when it is dissolved in water. a compound that donates protons. a compound that accepts protons.

According  to  Arrhenius   An  acid  is  substance  that  increases H3O+  concentration  when  it  is dissolved  in  water.  An  acid  dissociate  in water  to  form H3O+  ions.  The  H3O+  give the  substance  its  acidic  characteristic when  they  dissolve in  water  while  OH-   give  substance  its  basic  characteristic.

Because a model would make the investigation easier to understand