_E06-GC01-Calorimetry Lab notebook

pdf

School

Florida International University *

*We aren’t endorsed by this school

Course

2165

Subject

Chemistry

Date

Feb 20, 2024

Type

pdf

Pages

Uploaded by BaronSummer2879

Make a copy of this document as a Google Doc. Rename it according to the Experiment you will be working on (e.g. Exp06-GC01-Calorimetry-LastName). Upload it to the folder assigned to you by your instructor. You will work on your copy of the Google Doc (it will be a living document that you will update as you work on the experiment). Text and data entry made by you should be formatted in blue font . You will upload a pdf copy of this document in two different instances. Read instructions below. 1. During the lab you will complete the Summary Statement of Purpose, Experiment Description, Safety Focus, Experiment Observations, and Data Tables. 2. After lab you will: a. Complete any calculations (you must provide at least one description or equation that shows your work), insert any additional graphs, charts, or tables. b. From your observations made during the lab and results of calculations, highlight the key conclusions of the experiment. These should be bullet point statements. 3. Once you’re done: a. Download a pdf copy and upload it to Canvas to the Lab Notebook Assignment. b. Upload the same pdf to Canvas to the Data Analysis Assignment. Summary Statement of Purpose The objective of this experiment is to: (1) Calculate moles using molar mass. (2) Explain what is meant by an aqueous solution including solvent and solute. (3) Calculate moles of solute given molarity and volume. (4) Identify the limiting reagent and calculate moles of reaction product using solution stoichiometry. (5) Define and calculate heat of a reaction using calorimetry. (6) Explain how the amount (in grams) & concentration (in mol/L) of the reactants affect reaction heat released and reaction heat per mole released. (7) Explain how the amount (in grams) of solid dissociation in water affects heat and heat per mole released. The safety purpose of this experiment: (1) Practice developing a hypothesis for a proposed experiment. (2) Continue developing an understanding of the safety role eye and skin protection play when in the lab setting.

(3) Practice the safe and proper handling and disposal of corrosive chemicals. Experiment Description Observations Describe each step of the procedure. You may cut and paste the procedure. You should start this section before coming to the lab and continue to edit it during the lab. In this section you will record relevant observations of the experiment, hypothesis, any modifications to the experiment, mistakes, and/or notes from your instructor PART A In this part, you will determine the amount of heat exchanged when solid sodium hydroxide is dissolved in a solution of hydrochloric acid. Your instructor will assign individuals with the amounts indicated in table A. Table A. Individual Assignments Part A Individual NaOH (g) Concentration of HCl (M) 1 2.0 0.2421 2 3.0 0.3966 3 4.0 0.5371 Reaction NaOH (s) + HCl (aq) ⟶ NaCl (aq) + HOH (l) Question 1: hypothesis The reaction between NaOH (s) and HCl (aq) is exothermic. You will test different combinations of grams of NaOH and concentrations of HCl (See Hypothesis 1:

Table A). Will the amount of heat released by the reaction of NaOH (s) and HCl (aq) be the same or different for each different combination? Prior to running your reactions, write down your hypothesis in the observations section of your lab notebook. a Your instructor will explain how to set up the calorimeter in the laboratory. The thermometer should measure the temperature to +0.2°C. b. Transfer 200 mL of the assigned concentration of HCl (aq) with a graduated cylinder into the calorimeter. Record the molarity of HCl in Table 1 of your lab notebook data section. Insert a thermometer or stirrer to mix the acid solution and record the temperature in Table 1 of your lab notebook data section.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

c. Determine and record the mass of the assigned sample of solid pellets of NaOH to the nearest 0.01g in Table 1of your lab notebook data section. Important Note : It is difficult to weigh out the exact mass of NaOH(s) since it absorbs moisture from the air. If using standard-size NaOH pellets, ~19 pellets = 2 grams. Don’t forget to record in your table the moles of HCl and NaOH utilized. d. Transfer quickly the weighed NaOH pellets into the calorimeter containing the acidic solution. Stir the solution promptly and record the highest temperature in Table 1of your lab notebook data section. PART B Measuring the Heat of Reaction: NaOH (aq) + HCl (aq) Reaction: NaOH (aq) + HCl (aq) ⟶ NaCl (aq) + HOH (l) The data collected for this part of the experiment will be done in a similar fashion from Part A. The instructor will assign individuals based on the table below: Hypothesis 2:

Table B. Individual Assignments Part B Individual HCl (aq) in M NaOH 1 0.2421 0. 2 0.3966 0. 3 0.5371 0. In this part, you will mix 100mL of a Sodium Hydroxide solution with 100mL of Hydrochloric Acid solution. You will test different concentrations. Look at the concentrations in Table B. Question 2: hypothesis Will the amount of heat released by the reaction of NaOH (aq) and HCl (aq) be the same or different for each different combination? Write down your hypothesis in the observations section of the lab notebook.

Record your initial temperature and final temperature in Table 2 of the lab notebook data section. a. Transfer 100 mL of assigned HCl solution into the calorimeter. Record molarity in Table 2 of the lab notebook data section. b. Transfer 100 ml of assigned NaOH solution into a 250mL beaker. Record the molarity in Table 2 of the lab notebook data section. c. Measure the initial temperature for each solution and record in Table 2 of the lab notebook data section. d. Combine both solutions in the calorimeter and record the maximum temperature reached as the final temperature in Table 2 of the lab notebook data section. e. Discard the solution per instructor directions. f. Compare your results with the class and compile the data of the different individuals in the classroom in Table 2 of the lab notebook data section. .

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

PART C Enthalpy of NaOH Solution Reaction NaOH (s) → NaOH (aq) In this part you will predict, based on results of ∆H from Part A and Part B, the enthalpy of the dissociation of NaOH(s) in distilled water (See equation above). You will be essentially combining the equations from Parts A and B to isolate the solvation of sodium hydroxide. In part A the NaOH first needed to dissolve, then react. In part B it was already dissolved. Therefore, the differences in the molar enthalpies of those two reactions give us clues as to the enthalpy of solvation. Hypothesis Prior to performing your reactions, record your hypothesis in the observations section of the lab notebook. How does the unknown ∆H for Part C compare to the ∆H from Part A and Part B? a. Measure 200 mL of distilled water at room temperature and transfer into the calorimeter. Record your initial temperature in Table 3 of the lab notebook data section. Hypothesis 3:

a. Weigh the amount of NaOH assigned to 0.01g. Note: be careful with the NaOH pellets. b. Transfer the solid NaOH into the calorimeter with deionized water. Stir and record the highest temperature in your table. Record the final temperature in Table 3 of the lab notebook data section. Neutralize the solution and dispose of it as indicated by your instructor. Table C. Individual Assignments Part C Individual NaOH(s) in grams 1 2.0 2 4.0 3 6.0

During lab Safety Focus Record the Safety Focus of the week. Any relevant information you need to keep in mind when working in the lab. eye & skin protection when using corrosive chemicals Liquid corrosive chemicals are those with a pH <= 4.0 or a pH >= 9. Solid chemicals are considered corrosive when in solution; they fal highly corrosive chemical has a pH <= 2 and >= 12.5. Strong acids [HCl, HNO3, H2SO4] Strong bases [NaOH, KOH] Personal protective equipment 1.Avoid Skin Contact. Wear protective gloves, aprons, boots, hoods, or other clothing. 2.Protect Your Eyes and Face: chemical splash goggles are best; in some cases you should also wear a face shield (with chemical splash goggles) What do I do if a corrosive comes in contact with the skin? Flush contaminated eyes or skin with water for at least 20-30 minutes, sometimes longer, in case of accidental contact. Call immediately for medical assistance.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Corrosives and ventilation Store, handle, and use corrosives in well-ventilated areas. Always work with concentrated acids in a fume hood to avoid spreading the fumes into the lab area. Can I add corrosives to water? Sometimes, a job requires mixing corrosives with water. Many corrosive materials, both liquid and solid, generate large amounts of heat when they are mixed with water. This can cause the solution to froth and boil or even to erupt violently from the container. For example, a glass of water thrown into a bucket of concentrated sulfuric acid is converted instantly to steam which will eject the entire contents of the bucket into the air. For this reason, always add corrosives to water, slowly, in small amounts, with frequent stirring. Always use cold water. Where should corrosives be stored? In general, store corrosives separately, away from processing and handling areas, and from other materials. Separate storage can reduce the amount of damage caused in case of fires, spills or leaks. If totally separate storage is not possible, store corrosives away from incompatible materials.Some corrosives are incompatible with each other. For example, acids and bases react together, sometimes violently. Do not store them beside each other. Data Tables Insert any Data Tables that you will need to complete during the lab. Hint: you should prepare your Data Tables before the lab and fill in the information during the lab. Table 1 Heat of Dissolution of NaOH(s) in HCl solution

Individual 1 2 3 Mass of NaOH (g) 2 3 4 Vol HCl (mL) 200 200 200 Conc. of HCl (M) 0.2421 0.3966 0.5237 Initial temp (°C) 31.8 20.8 21.7 Final temp (°C) 29.1 30.2 30.9 Table 2 Heat of Reaction of NaOH (aq) and HCl (aq) Solution Individual 1 2 3 Molarity of NaOH (M) 0.2468 0.4861 0.7180 Molarity of HCl (M) 0.2421 0.0396 0.0537 Initial Temp (°C) 21.2 21.35 24.7 Final Temp (°C) 23 24.1 25.4 Table 3 Enthalpy of NaOH Solution

Individual 1 2 3 Mass of NaOH (g) 2 4 6 Initial Temp (˚C) 23.6 23.8 24.9 Final Temp (˚C) 29.4 28.6 35.3 Calculations You must show your work. If you’re repeating calculations you must show your work for at least one example. Interpretation and Evaluation of Data (Highlights, Experimental Challenges and Conclusions) Part A Analysis Reaction NaOH (s) + HCl (aq) ⟶ NaCl (aq) + HOH (l) Use your data from data table 1 to complete the following table. Provide one sample calculation for EACH row completed. Assume that the specific heat of the solution is the same as that of water, 4.184 J/(g ºC) , and that the density of the solution is 1.0 g/mL. Also assume that any heat exchange between the calorimeter and surroundings is negligible. ΔH: Molar enthalpy ∆𝐻 = 𝑞 ????? ?? ?????????

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Watch your units! Table 1 Heat of Dissolution of NaOH(s) in HCl solution Individual 1 2 3 Mass of NaOH (g) 2 3 4 Vol HCl (mL) 200 200 200 Conc. of HCl (M) 0.2421 0.3966 0.5237 Initial temp (°C) 31.8 20.8 21.7 Final temp (°C) 29.1 30.2 30.9 ∆T (°C) -2.7 9.4 9.2 q ( J ) -564.88 1966.84 1924.64 Moles of HCl 0.04 0.04 0.04 ∆H per mole of HCl ( kJ /mol) -12.408 49.171 48.116 Moles of NaOH ∆H per mole of NaOH ( kJ /mol) ∆H per mole of reaction occurrences ( kJ /mol)* *you will note that your base and acid are not present in equimolar amounts. You must determine which is the limiting reactant. This is the one that determines how many reaction occurrences there are.

Part B Analysis Reaction: NaOH (aq) + HCl (aq) ⟶ NaCl (aq) + HOH (l) Use your data from data table 2 to complete the following table. Provide one sample calculation for EACH row completed. Watch your units! Table 2 Heat of Reaction of NaOH (aq) and HCl(aq) Solution Individual 1 2 3 Molarity of NaOH (M) 0.2468 0.4861 0.7180 Molarity of HCl (M) 0.2421 0.0396 0.0537 Initial Temp (°C) 21.2 21.35 24.7 Final Temp (°C) 23 24.1 25.4 ∆T (°C) 1.8 2.75 .7 q absorbed by the solution (J) Moles of HCl

Moles of NaOH Moles of H 2 O produced ∆H per mole of H 2 O (kJ/mol) Summarize your ∆ H (kJ/mol) results from Part A and Part B in the summary table below. (Use the ∆ H per mole of reaction occurrences for Part A) Summary Table Individual 1 2 3 Average ∆H Part A (kJ/mol ) ∆H Part B (kJ/mol ) Part C Analysis Reaction NaOH (s) → NaOH (aq)

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Use your data from data table 3 to complete the following table. Provide one sample calculation for EACH row completed. Watch your units. Table 3 Enthalpy of NaOH Solution Individual 1 2 3 Mass of NaOH (g) Initial Temp (˚C) Final Temp (˚C) ∆T (˚C) Moles of NaOH q* ( J ) Heat liberated per mole of NaOH (s) ( kJ /mol) (ΔH) *Remember, due to conservation of energy the q here represents both the heat absorbed by the solution, and the heat released as sodium hydroxide is dissolved Average ΔH of dissolving sodium hydroxide: ____________________________

Based on your data analysis, answer the following questions. 1. How does your hypothesis for each part of this experiment compare to the simulation results? Respond for each hypothesis (Part A, Part B, and Part C) 2. Does the mass (in grams) or concentration (in mol/L) of the reagents affect the reaction heat released (q) in part A and B? Support your answers with specific examples from the data compiled. 3. Does the mass (in grams) or concentration (in mol/L) of the reagents affect the reaction heat per mole liberated in part A and B? Support your answers with specific examples from the data compiled. [Think: do you have these results summarized to help the comparison?] 4. Based on the data recorded in Table 3, a. is the amount of heat released related to the mass of solid NaOH dissociated in deionized water? Explain your reasoning. b. Is the amount of heat per mole released related to the mass of solid NaOH dissociated in deionized water? Explain your reasoning. Experimental Challenges & proposed changes: Here you will briefly outline logistical experimental challenges that could be

improved upon for reproduction of the experiment. Each suggestion must be accompanied by a statement of how your suggestions might allow the experimenter to obtain higher quality data or reach stronger conclusions. [Minimum of two]. Overall conclusions: This component should not contain new information. It should address how the experiment arrived or did not arrive at the statement of purpose and summarize how this is true. Think of this as a concise 2-3 sentence statement restating the key findings of the experiment.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

_E06-GC01-Calorimetry Lab notebook

Related Documents