Electrolytes Worksheet Name: _______KEY_________ 1. Substances are classified as either soluble or insoluble in water. When a substance dissolve in water it forms a(n) aqueous solution. 2. A substance that does not dissolve in water is called insoluble. 3. A water soluble substance is classified as either an electrolyte or a non-electrolyte. 4. An electrolyte is a substance whose aqueous solution conducts electricity. 5. A substance whose aqueous solution does not conduct electricity is called a non-electrolyte. 6. In order for a solution to conduct electricity, it must contain ions. 7. If we were able to examine an aqueous solution of table salt, NaCl (aq), at the molecular level, we would see individual sodium and chloride ions, Na+ and Cl-, hydrated. That is they are separated, dispersed and surrounded by water molecules. Therefore, table salt is classified as a(n) electrolyte. 8. If we were able to examine an aqueous solution of table sugar at the molecular level, we would see the individual sugar molecules hydrated. That is they are intact, dispersed and surrounded by water molecules. Therefore, table sugar is classified as a(n) non-electrolyte. 9. Electrolytes break into ions as they dissolve in water. A compound that breaks entirely into ions as it dissolves in water is classified as strong electrolyte. A compound that breaks partially into ions as it dissolves in water is classified as a weak electrolyte. 10. At the same molar concentration, a strong electrolyte is a much better conductor than a weak electrolyte. 11. Compounds that are classified as strong electrolytes and therefore break entirely into ions in dilute aqueous solutions are: strong acids, strong bases, and soluble salts. 12. There are seven common strong acids. List their names and formulas: HCl hydrochloric acid HBr hydrobromic acid HI hydroiodic acid HNO3 nitric acid HClO3 chloric acid HClO4 perchloric acid H2SO4 sulfuric acid 13. There are eight common strong bases. List their names and formulas: LiOH lithium hydroxide NaOH sodium hydroxide KOH potassium hydroxide RbOH rubidium hydroxide CsOH cesium hydroxide Ca(OH)2 calcium hydroxide Sr(OH)2 strontium hydroxide Ba(OH)2 barium hydroxide 14. A salt is an ionic compound that is neither an oxide nor a hydroxide. Among the following ionic compounds, NaNO3 is a salt, Zn(OH)2 and CaO are not salts. 15. There are too many soluble salts. In order to determine whether a salt or any other ionic compound is soluble or not, one has to check the solubility rules. 16. It is good to know that compounds of Group IA ions are soluble in water. + 17. It is helpful to know that compounds that contain the ammonium ion, NH4 , are soluble in water. - 18. It is helpful to know that compounds that contain the nitrate ion, NO3 , are soluble in water. 19. Weak electrolytes include substances that are weak acids and weak bases. 20. The most common weak base is ammonia whose molecular formula is NH3. 21. Acetic acid, CH3COOH, is a carboxylic acid and is classified as a weak acid. 22. A hydroxide like Cu(OH)2, that is not one of the eight common strong bases is classified as a(n) insoluble base. .