5. Which solutions in question 1 would you expect to react with sodium chloride solution (Reagent 4)? Write the hypotheses based on the information on the previous page. 6. Which solutions in question 1 would you expect to react with sodium hydroxide solution (Reagent 5)? Write the hypotheses based on the information on the previous page. Hint–there is more than one! Be sure to get them all! Now show your answers to your lab instructor to check your understanding. When you are approved you can put on your goggles and do the experiment to determine the identity of the ions in the bottles labeled AY, BY, BZ, CX, CY, DX, DZ. Each letter stands for the same ion each time. Important sure to record COLORS! Example–a student finds that EW and ET both react with Reagent 4 to give a white ppt. The E in both cases must be silver...remember positive ions are always written first! The silver ions would have been in solution with two different negative ions, maybe nitrate and sulfate. Since the negative ions do NOT react with Reagent 4, they do not make a difference. Experimental Procedure 1. Each person from the group checks out (1) spot plate from the stockroom. a. Make sure that the wells are CLEAN before commencing the experiment. Dirty spot plates could give erroneous results. b. Use DI H2O and the cotton swabs to clean the wells if necessary. 2. As a group test all seven solutions: AY, BY, BZ, CX, CY, DX, and DY with Reagent 1. a. First, place 2 drops of each solution in each of seven wells on the spot plate. b. Then, add 2 drops of Reagent 1 to all seven wells. c. Record the results in the data table. No reaction is indicated as NR. PPT indicates formation of a solid or cloudiness. Solution AY BY BZ CX CY DX DZ
5. Which solutions in question 1 would you expect to react with sodium chloride solution (Reagent 4)? Write the hypotheses based on the information on the previous page. 6. Which solutions in question 1 would you expect to react with sodium hydroxide solution (Reagent 5)? Write the hypotheses based on the information on the previous page. Hint–there is more than one! Be sure to get them all! Now show your answers to your lab instructor to check your understanding. When you are approved you can put on your goggles and do the experiment to determine the identity of the ions in the bottles labeled AY, BY, BZ, CX, CY, DX, DZ. Each letter stands for the same ion each time. Important sure to record COLORS! Example–a student finds that EW and ET both react with Reagent 4 to give a white ppt. The E in both cases must be silver...remember positive ions are always written first! The silver ions would have been in solution with two different negative ions, maybe nitrate and sulfate. Since the negative ions do NOT react with Reagent 4, they do not make a difference. Experimental Procedure 1. Each person from the group checks out (1) spot plate from the stockroom. a. Make sure that the wells are CLEAN before commencing the experiment. Dirty spot plates could give erroneous results. b. Use DI H2O and the cotton swabs to clean the wells if necessary. 2. As a group test all seven solutions: AY, BY, BZ, CX, CY, DX, and DY with Reagent 1. a. First, place 2 drops of each solution in each of seven wells on the spot plate. b. Then, add 2 drops of Reagent 1 to all seven wells. c. Record the results in the data table. No reaction is indicated as NR. PPT indicates formation of a solid or cloudiness. Solution AY BY BZ CX CY DX DZ
Precipitation-Reactions-in-Aqueous-Solutions.docx