In one to two sentences give one reason reactants might not equal visible products after a chemical reaction

If your asking why they are different because atoms are rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both reactants and products for them to be the same.

i'm pretty sure its b i might be wrong though!

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.