March 20,2013 Amber McCollum
Introduction
Stoichiometry is a branch of chemistry that deals with the quantitative relationships that exist among the reactants and products in chemical reactions To predict the amount of product produced in a precipitation reaction using stoichiometry, accurately measure the reactants and products of the reaction, determine the actual yield vs. the theoretical yield and to calculate the percent yield. The equation that will be used is:
Ba(NO3)2 (aq) + CuSO4 (aq) → BaSO4 (s) + Cu(NO3)2 (aq)
Method 1. Gather materials needed for experiment which included: a. Small test tube with lip b. Large beaker c. Small graduated cylinder d. Large graduated cylinder e. One 9in balloon f. Citric acid g. Sodium bicarbonate h. Sodium chloride
2. To start the experiment: * Na2CO3(aq) + CaCl2. 2H2O(aq) à CaCO3(s) + 2NaCl(aq) + 2H2O * Put on your goggles. * Weigh out 1.0 g of CaCl2·2H2O and put it into the 100-mL beaker. Add 25 mL of distilled water and stir to form the calcium chloride solution. Use only distilled water since tap water may have impurities that interfere with the experiment.. Use stoichiometry to determine how much Na2CO3 you will need for a full reaction. * Weigh the calculated amount of Na2CO3 and put it in a small paper cup. Add 25 mL of distilled water and stir to make a sodium carbonate solution. * Pour the sodium carbonate solution from the paper cup into the beaker with the calcium chloride solution. A precipitate of calcium carbonate will form instantly. * Use the following instructions to set up a filtration assembly. * Swirl the contents of the beaker to dislodge any precipitate from the sides. Then, while holding the filter paper in place and open, slowly pour the content of the beaker into the filter paperlined funnel. Be careful to not let the solution overflow the level of