How to approach a lab write up for EXP 23C
Name
Date (of experiment)
 
Title of experiment: (as listed in manual/handout)
 
Purpose or Aim: This says exactly what the goal of the experiment is. It may consist of one or more parts. Based on what is stated in the procedure, you should have a very good idea as to what the point of the experiment is. Explicitly and briefly state all in this section. (2 points)
 
Examples: 1. To recrystallize an impure sample of benzoic acid; 2. To determine the melting point of salicylic acid
 
Introduction: This explains the theory behind the experiment. Give some general background as to what the experiment is about. Include definitions of any key concepts that are an important part of the experiment. (5 points)
This approach can be applied across all topics being covered.
 
Materials: List glassware, chemicals and equipment/instrumentation used in the experiment.
(5 points)
 
 
Procedure: Write a step by step procedure of the experiment as outlined in the video. (5points)
 
 
 
 
 
 
 
 
Results and calculations: Report results from experiment. Tables can be used, also show sample calculations. (10 points)
 
Mass of 5 mL Conical Vial
Mass of 5 mL Conical Vial + t-pentylalcohol
Mass of t-pentylalcohol
 
Theoretical yield of t-pentylchloride    (5 pts)
 
 
Mechanism for reaction (5 pts)
 
 
Discussion: Analyze the data you obtained in your experiment. Explain difference between the starting weight of the impure sulfanilamide and the pure sulfanilamide. (5 points)
 
 
 
Questions (t-pentylchloride 1-5 pg 206) ( 18 points)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
How to approach a lab write up for EXP 18
Name
Date (of experiment)
 
Title of experiment: (as listed in manual/handout)
 
Purpose or Aim: This says exactly what the goal of the experiment is. It may consist of one or more parts. Based on what is stated in the procedure, you should have a very good idea as to what the point of the experiment is. Explicitly and briefly state all in this section. (3 points)
 
Examples: 1. To recrystallize an impure sample of benzoic acid; 2. To determine the melting point of salicylic acid
 
Introduction: This explains the theory behind the experiment. Give some general background as to what the experiment is about. Include definitions of any key concepts that are an important part of the experiment. (5 points)
This approach can be applied across all topics being covered.
 
Materials: List glassware, chemicals and equipment/instrumentation used in the experiment.
(5 points)
 
 
Procedure: Write a step by step procedure of the experiment as outlined in the video. (5points)
 
 
 
 
 
 
 
 
Results and calculations: Report results from experiment. Tables can be used, also show sample calculations. (20 points total)
 
Fermentation of Sucrose
 
Measuring Sucrose (3pts)
Mass of weight boat
Mass of weight boat +Sucrose
Mass of sucrose
 
Measuring yeast (3pts)
Mass of weight boat
Mass of weight boat + yeast
Mass of yeast
 
Fractional distillation (3pts)
Mass of empty vial
Mass of vial + distillate
Mass of distillate
 
Measuring Density of distillate at 25°C (3pts)
Mass of empty vial
Mass of empty vial and 1.000 mL of distillate
Mass of 1.000 mL of distillate
 
Density of distillate (2pts)
Percent ethanol by weight (2pts)
% Yield of ethanol = (mass of ethanol/theoretical yield) * 100 (4pts)
 
 
Discussion: Analyze the data you obtained in your experiment. Explain difference between the starting weight of the impure sulfanilamide and the pure sulfanilamide. (5 points)
 
Conclusion: (2 points)
 
Post lab calculations: (pg. 156)
 
Questions (1 and 6) (5 points)
For question 6, at room temperature and pressure (1 atm and 25 °C) one mole of a gas occupies 24 Liters.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

• chemistry
   Complete the inquiry questions in the handout using the procedure in this video

  print out the pdf file and fill out the answers, or write answers on separate sheets of papers but CLEARLY indicate the number of the question before each one. Please send pictures of the final product in one pdf file.
• Experiment 19: Reactivities of Some Alkyl Halides
  Overview
  Use this document to record your observations, analyze the results, and reflect on the mechanisms of the
  substitution reactions observed in Experiment 19.
  Some of the questions in this document will refer to the elementary steps in organic reactions as well
  as the reaction types that were taught in general chemistry. You may refer to the lists below.
  Table 1. Common elementary steps for organic compounds and inorganic reaction types.
  Organic Chemistry Elementary Steps
  General Chemistry Reaction Types
  • Coordination
  • Heterolysis
  • Bimolecular nucleophilic substitution
  • Bimolecular elimination
  • Nucleophilic addition
  • Nucleophile elimination
  • Electrophilic addition
  • Electrophile elimination
  • Carbocation Rearrangement
  • Proton Transfer
  • Precipitation
  • Single Replacement
  • Double Replacement
  • Acid/Base neutralization
  • Combustion
  • Redox
  • Synthesis
  • Decomposition
  Part A. Sodium Iodide in Acetone
  Introduction
  1) Before we analyze the data associated with Experiment 19, Part A, let’s be sure that we understand the
  chemical reactions being observed. Although we will not be testing alkyl bromide X, shown below, it
  would be expected to undergo substitution under the reaction conditions of the experiment.
  a. First, X would undergo an “organic chemistry elementary step”. On the figure below, draw the
  curved arrows for this step, provide the structures of all products (organic and inorganic) in the
  box, and name the elementary step.
  b. One of products of step 1 undergoes a reaction type that you considered in general chemistry.
  On the figure below, name the type of reaction and provide the identity of the white powder
  that would be observed had we studied alkyl halide X in the experiment.
  Figure 1. How alkyl bromide X would react under the conditions of Exp. 19, Part A.
  a)
  b)
  NaI
  Br
  acetone
  alkyl bromide X
  product(s) of step 1
  white precipitate
  “organic” chemistry
  “general” chemistry
  elementary step 1:
  reaction type:
  2) If a reaction occurs for an alkyl halide in Part A, it will be a (circle one): SN1 or SN2 reaction? How do
  each of the following factors affect whether or not (or how fast) a reaction will occur in Exp. 19, Part A?
  a. Solvent (same for all alkyl halides in Exp 19, Part A)
   
  b. Nucleophile (same for all alkyl halides in Exp 19, Part A)
   
  c. Structure of the alkyl halide (will vary in Exp 19, Part A)
   
  d. Leaving group (may vary in Exp 19, Part A)
   
  Results
  3) Now we are ready to consider the alkyl halides that were tested in Exp 19, Part A.
  a. Draw the bond-line structures of each alkyl halide tested (note: crotyl chloride, tube 6, was
  omitted).
  b. **Read the procedure**, view the video of the experiment and record the results. Be sure to
  include the results at room temperature AND elevated temperature when appropriate.
  c. For the alkyl halides that reacted, draw the bond-line structures of the major organic product.
  d. Finally, for each tube (regardless of whether or not a reaction occurred), explain the results.
  Your analysis should be based on structure, the mechanism of the organic reaction occurring
  (or not occurring) and the factors that affect the rate law of that reaction type. You may find
  words and drawings are helpful for a complete explanation.
  Tube
  #
  Bond-line Structure of
  Alkyl Halide
  Result(s) Bond-line Structure of
  Product
  (or “NA” if no reaction)
  Analysis ( = an Explanation, based
  on structure)
  1
  2
  3
  4
  5
  7
  8
  9
  10
  Reflect
  4) Refer back to Figure 1. Would we have been able to analyze whether or not the organic reaction
  occurred without the “general chemistry reaction” (part b)? Why or why not? (Answer in one
  sentence.)
  5) Consider crotyl chloride, shown below.
  a. Draw a complete curved arrow mechanism for how crotyl chloride could react under the
  conditions of this experiment.
  b. Provide the structures of all products (organic and inorganic).
  c. Then, predict: would you expect to observe a reaction for crotyl chloride under these
  conditions? Explain your answer in one sentence.
  NaI
  Cl
  acetone
  Prediction (select one):
  A reaction would NOT be observed at any
  temperature.
  A reaction would only be observed at
  elevated temperature.
  A reaction would be observed at BOTH room
  and elevated temperatures
  crotyl chloride
  all products (organic and inorganic)
  complete curved-arrow mechanism leading to the proposed products:
  Explanation for prediction:
   
  6) For each pair of reactions: draw the structure of the substitution product, circle the reaction that
  would proceed with the fastest rate (if they have the same rate, circle “same”), and explain your
  answer in one sentence, referring to structure, mechanism, and rate law.
  a)
  NaI
  NaI
  Cl
  Br
  acetone
  same
  acetone
  explanation:
  b)
  I
  I
  NaCN
  NaCN
  same
  acetone
  acetone
  explanation:
  Part B. Silver Nitrate in Ethanol
  Introduction
  1) Before we analyze the data associated with Experiment 19, Part B, let’s be sure that we understand the
  chemical reactions being observed. Although we will not be testing 1-bromo-1-methylcyclopentane,
  shown below, it would be expected to undergo substitution under the reaction conditions of the
  experiment.
  a. First, the alkyl bromide would undergo an “organic chemistry elementary step.” On the figure
  below, draw the curved arrows for this step, provide the structures of all intermediates (organic
  and inorganic) and name the elementary step.
  b. One of products of step 1 undergoes a reaction type that you considered in general chemistry
  class. On the figure below, name the type of reaction and provide the identity of the white
  powder that would be observed had we studied this alkyl halide in the experiment.
  c. The other product of step 1 continues to undergo a series of “organic chemistry elementary
  steps.” Draw the complete curved-arrow mechanism for these steps, naming each one (see:
  Organic Chemistry Elementary Steps). Circle the final organic product of this reaction.
  Figure 2. How 1-bromo-1-methylcyclopentane would react under the conditions of Exp. 19, Part B.
  “general” chemistry
  reaction type:
  a)
  “organic” chemistry
  elementary step 1:
  b)
  Br
  EtOH, AgNO3(EtOH)
  EtOH, AgNO3(EtOH)
  intermediate(s)
  white precipitate
  c)
  the rest of the mechanism (label each elementary step with its name and circle the final organic product):
  2) If a reaction occurs for an alkyl halide in Part B, it will be a (circle one): SN1 or SN2 reaction? How do
  each of the following factors affect whether or not (or how fast) a reaction will occur in Exp. 19, Part B?
  a. Solvent (same for all alkyl halides in Exp 19, Part B)
  b. Nucleophile (same for all alkyl halides in Exp 19, Part B)
  c. Structure of the alkyl halide (will vary in Exp 19, Part B)
  d. Leaving group (may vary in Exp 19, Part B)
  Results
  3) Now we are ready to consider the alkyl halides that were tested in Exp 19, Part B.
  a. Draw the bond-line structures of each alkyl halide tested (note: crotyl chloride, tube 6, was
  omitted).
  b. **Read the procedure**, view the video of the experiment and record the results. Be sure to
  include the results at room temperature AND elevated temperature when appropriate.
  c. For the alkyl halides that reacted, draw the bond-line structures of the major organic product.
  d. Finally, for each tube (regardless of whether or not a reaction occurred), explain the results.
  Your analysis should be based on structure, the mechanism of the organic reaction occurring
  (or not occurring) and the factors that affect the rate law of that reaction type. You may find
  words and drawings are helpful for a complete explanation.
  Tube
  #
  Bond-line Structure of
  Alkyl Halide
  Result(s) Bond-line Structure of
  Product
  (or “NA” if no reaction)
  Analysis ( = an Explanation, based
  on structure)
  1
  2
  3
  4
  5
  7
  8
  9
  10
  Reflect
  4) Refer back to Figure 1. Would we have been able to analyze whether or not the organic reaction
  occurred without the “general chemistry reaction” (part b)? Why or why not? (Answer in one
  sentence.)
  Do you expect that crotyl chloride would react under the conditions of Part B? Why or why not?
  (Explain your answer with clearly drawn structures, referring to the rate law of this reaction).
  5)
  Cl
  crotyl chloride
  6) For each pair of reactions: draw the structure of the product, circle the reaction that would proceed
  with the fastest rate (if they have the same rate, circle “same”), and explain your answer in one
  sentence, referring to structure, mechanism, and rate law.
  a)
  Cl
  Br
  EtOH
  EtOH
  same
  explanation:
  b)
  I
  I
  same
  EtOH
  EtOH
  explanation:
  Summarize and Reflect
  You do not need to submit your answers to these questions, but you should take the time to answer them.
  1) What did you learn in this experiment?
  2) Overall, did alkyl halides undergo only one type of substitution reaction (only react in either part A or
  part B) or did some alkyl halides undergo both types of substitution reactions (react in both parts A and
  B)? Can you describe any patterns?
  3) Consider the factors that affect the rate of substitution reactions (make a list). For each factor consider
  if it affects the rates of SN1 and SN2 in the same or different ways (or not at all).
  4) What questions do you have?