Unit 6 Lab Assignment Chemistry Unit 6 Laboratory: Stoichiometry of Chemical Reactions

Unit 6 Lab Assignment Chemistry | Unit 6 | Laboratory: Stoichiometry of Chemical Reactions

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Directions: 1. Complete the tutorial for this lab: http://ktwelvecontent.next.ecollege.com/K12Content/Courses/resources/swfs/me dia/Eleventh_Grade/Science/Unit22289/Lesson87084/STOICH_FINAL.swf 2. Begin the lab using the procedures below and complete the data tables and questions as you complete the lab. When you have completed this assignment, submit this assignment to the drop box for the lab. Procedure: For each part, use the data table to set up your experiment. Add the indicated amount of the first reagent to each well. Next, add the indicated amount of the second reagent to each well. Stir each well with a clean stir rod. Observe and record your observations. For Part 1, complete the data table below to describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least copper(II) nitrate to the well with the most copper(II) nitrate. Which wells had the most distinct precipitate? Well Drops of Copper Drops of Sodium Color change (yes Precipitate (yes or Comments. Which # II Nitrate Hydroxide or no) no) well had the most color, the least, Record Color Record Color etc. 1A 5 45 2A 10 40 3A 15 35 4A 20 30 5A 25 25 6A 30 20 6B 35 15 6C 40 10 6D 45 5

Below is the balanced equation for the reaction. Review the results of your experiment and look closely over the mole ratio of the chemical reaction. Does your experiment reflect the stoichiometric, molar amounts indicated by the reactions? Discuss this using the evidence from your experiment.

Cu(NO3)2 (l) + 2NaOH (l)  Cu(OH)2 (s) + 2NaNO3 (l) Note: Cu(OH)2 is a blue precipitate. Unit 6 Lab Assignment Chemistry | Unit 6 | Laboratory: Stoichiometry of Chemical Reactions

For Part 2, describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least iron(II) sulfate to the well with the most iron(II) sulfate. Well Drops of Iron II Drops of Sodium Color change (yes Precipitate (yes or Comments. Which # Sulfate Hydroxide or no) no) well had the most color, the least, Record Color Record Color etc. 5 45 10 40 15 35 20 30 25 25 30 20 35 15 40 10 45 5 Below is the balanced equation for the reaction. Review the results of your experiment and look closely over the mole ratio of the chemical reaction. Does your experiment reflect the stoichiometric, molar amounts indicated by the reactions? Discuss this using the evidence from your experiment.

FeSO4 (l) + 2NaOH (l)  Fe(OH)2 (s) + Na2SO4 (l) Note: Fe(OH)2 is a dark green precipitate. Unit 6 Lab Assignment Chemistry | Unit 6 | Laboratory: Stoichiometry of Chemical Reactions

For Part 3, describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least iron(III) nitrate to the well with the most iron(III) nitrate. Well Drops of Iron III Drops of Sodium Color change (yes Precipitate (yes or Comments. Which # Nitrate Hydroxide or no) no) well had the most color, the least, Record Color Record Color etc. 5 45 10 40 15 35 20 30 25 25 30 20 35 15 40 10 45 5

Below is the balanced equation for the reaction in part 3. Review the results of your experiment and look closely over the mole ratio of the chemical reaction. Does your experiment reflect the stoichiometric, molar amounts indicated by the reactions? Discuss this using the evidence from your experiment.

Fe(NO3)3 (l) + 3NaOH (l)  Fe(OH)3 (s) + 3NaNO3 (l) Note: Fe(OH)3 is a red-orange precipitate.