Pre-lab assignment(s) 1) Define the terms filtrate, residue, precipitate, limiting reactant, and excess reactant. 2) Explain the difference between decantation and filtration. 3) Write the balanced equation for the reaction of aqueous sodium carbonate and aqueous calcium chloride dihydrate to form solid calcium carbonate and aqueous sodium chloride. Include phase labels for each reactant and product. (Don't forget the water released from the hydrate.) 4) Write the complete ionic and net ionic equations for the precipitation reaction being done in this experiment. Circle the spectator ions in the complete ionic equation. 5) We will use chemical tests to determine the excess reactant, as some of that reactant will be present in the filtrate(it was in excess). For each test described below, write the molecular, complete ionic and net ionic chemical equations describing the chemical reaction. Indicate which reactant (and which ion in the reactant specifically) is being tested for that will be found the filtrate. Include phase labels. The first one is completed as an example a. If calcium chloride dihydrate is the reactant in excess, calcium ions will end up in the filtrate. Treatment of a sample of the filtrate with aqueous sodium hydroxide will result in a white precipitate, which is an indicator of the presence of calcium ions. + Molecular: CaCl2 · 2H₂O(aq) + 2NaOH(aq) →Ca(OH)2(s) + 2NaCl(aq) + H2O(1) Complete ionic: Ca²+ 2Cl(aq) + 2H₂O(1) + 2Na(ªq) + 2OH(aq) → Ca(OH)2(s) +2Cl(aq) + 2H₂O + 2Na(q) Net Ionic equation: Ca(aq) 2+ + 2OH(aq) → Ca(OH)2(s) (aq) b. If calcium chloride dihydrate is the reactant in excess, calcium ions will end up in the filtrate. Treatment of a sample of the filtrate with aqueous sodium carbonate will result in a white precipitate. c. If sodium carbonate is the reactant in excess, carbonate ions will end up in the filtrate. Treatment of a sample of the filtrate with aqueous calcium chloride will result in a white precipitate. d. If sodium carbonate is the reactant in excess, carbonate ions will end up in the filtrate. Treatment of a sample of the filtrate with hydrochloric acid will result the production of effervescence. What physical evidence would indicate this reaction occurred? e. After analysis of the net ionic equation for the production of calcium carbonate, do you think we should perform chemical tests for the chloride or sodium ions in the filtrate as an indication of the excess reactant? Explain.