14 Industrial Inorganic Chemistry (INDL) Activity 2: The Solvay Process Purpose To illustrate reactions in the Solvay Process, and to produce sodium carbonate by an industrial process. Safety 1.    Wear protective goggles throughout the laboratory activity. 2.    Gloves for handling dry ice. 3.    Thoroughly wash your hands before leaving the laboratory. Procedure Part  I.  Preparation  of  NaHCO₃ 1.    Obtain a 250-mL gas collection bottle and stopper, 25 X 300-mm test-tube with a stopper assembly, and a length of rubber tubing (see Figure 1). 2.    Measure 60 mL 3 M NH₃ in a graduated cylinder and pour into a 250-mL Erlenmeyer flask. Weigh out 20 g NaCl to 0.1 g and add it to the NH₃ solution. Stopper tightly, and shake the solution for several minutes to saturate it with NaCl. If all the NaCl dissolves, add a bit more. When the solution appears to be saturated, filter out the excess solid, using a long-stemmed funnel and filter paper, letting the clear liquid drain into the test-tube. 3.    Assemble the apparatus shown in Figure 1. The long rubber tubing should be connected to the bent tube on the stopper assembly. The short straight tube is fitted with a small valve, called a Bunsen valve, which will vent CO₂ if the pressure becomesexcessive.ABunsenvalveconsistsofashortlengthofrubber tubing containing a short lengthwise slit.  The valve lets gas out, but not in. Fill  the  gas  collection  bottle about  half  full  with  crushed solid CO₂ (dry ice). Wrap the bottle with a towel or several papertowelsforinsulation,and put  it  into  a  600-mL  beaker. Insert the stopper firmly in the gas collection bottle. If your apparatus is tight, you willobservebubblesofCO₂inthe NH₃-NaClsolution;theyshould be produced at a vigorous rate, and as they bubble up through the solution they will react with NH₃  and  become  somewhat smaller.  As  the  reaction  goes on, the concentration of HCO₃ – ions  will  gradually  increase. Whilethereactionisproceeding, begin Part II of the experiment. However,  check  the  stoppers occasionally to make sure they haven’t popped out. LABORATORY ACTIVITY: STUDENT VERSION Figure 1. Apparatus for making NaHCO_3^. Towel Dry ice chunks 600 mL Beaker 250 mL Gas collection bottle 3 M NH₃ saturated with NaCl Tight-fitting stopper Solid glass rod Bunsen valve 25 x 300 mm Test-tube