What happens when salt is added to water? If I mix 1 cup of salt with 1 cup of water, will I end up with 2 cups of solution? – RT
As a crystalline solid, salt consists of a beautiful cubic lattice of sodium atoms that have lost one electron to become sodium positive ions and chlorine atoms that have gained one electron to become chlorine negative ions. The crystal is held together by the attractive forces between these oppositely charged atomic ions. When a salt crystal dissolves in water, it decomposes into individual sodium positive ions and chlorine negative ions that are then carried about by shells of water molecules. Water molecules are electrically polar, meaning that they have positively charged ends and negatively charged ends. The water molecules line up around a positively charged sodium ion with their negatively charged ends inward and carry that ion about. Similarly, water molecules line up around a negatively charged chlorine ion with their positively charged ends inward and carry that ion about. Whether you will end up with 2 cups of solution after mixing 1 cup of salt and 1 cup of water depends on how tightly the atoms and molecules pack together in each case. Remember that your 1-cup of salt contains a fair amount of air between the salt grains. You’ll have to try it to find out the answer—I’m not sure what the answer will be.