Answer to Question #251275 in General Chemistry for putus

Question

In order to test Billy's hypothesis, 6 groups of lab students were given the following rules to follow:

• Each group must perform the synthesis of CaCO₃ three times
• Each group will use the same amount of Na₂CO₃: 25 mL of a 0.5 M solution
• Each group will be assigned either 15, 25, or 35 mL of a 0.5 M CaCl₂ solution to use

Following these rules and the clues given in the puzzle, the groups worked together to come up with the following overall procedure to try and address both parts of Billy's hypothesis. 

Group 6's data differ greatly from the rest of the class. Based on the discussion of the suggested procedure and the the difference in their data, what step do you think group 6 may have forgotten? Explain your answer.

Answer 1

precipitate calcium carbonate from the reaction between sodium carbonate and calcium chloride