10.1: Enthalpy of Neutralization - Experiment
- Page ID
- 547478
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- Sodium hydroxide (\(\ce{NaOH}\)) and hydrochloric acid (\(\ce{HCl}\)) are corrosive and can cause skin burns or eye damage. If spilled, rinse immediately with plenty of water.
- Acetic acid (\(\ce{CH3CO2H}\)) is an irritant and should be handled carefully.
- Although this experiment involves small amounts of chemicals, acetic acid vapors can be irritating. Work in a well-ventilated area.
EQUIPMENT AND CHEMICALS NEEDED
| Equipment | Chemicals |
|---|---|
| Coffee-cup calorimeter with lid* | 1.0 M Sodium hydroxide (\(\ce{NaOH}\)) solution |
| Two temperature probes or thermometers | 1.0 M Hydrochloric acid (\(\ce{HCl}\)) solution |
| Beakers | 1.0 M Acetic acid (\(\ce{CH3CO2H}\)) solution |
| 10 mL graduated cylinder | |
| Hot plate |
*Note: The volumes used for this lab are based on the use of Flinn Scientific Small-Scale Calorimeters. Single-hole #6 rubber stoppers are used as a cover. Any small Styrofoam cup with a lid will work and volumes may need to be adjusted.
EXPERIMENTAL PROCEDURE
1. Connect & Setup
- Connect the Stainless Steel Temperature Probe to CH 1 on the LabQuest 3.
- Tap the Meter tab (gauge icon). You should see the live temperature.
2. Configure Graphing Mode
- Tap the Mode box.
- Select Time Based.
- Duration: 180 s (3 minutes) is usually sufficient.
- Rate: 2 samples/s.
- Tap OK.
3. Collection & Analysis
- Tap Start (Green Play) before you mix the chemicals to get a baseline.
- After mixing, watch the graph rise. Tap Stop (Red Square) when the temperature begins to drop again.
- Find Max/Min:
- Tap Analyze → Statistics.
- Check the box for Temperature.
- Record the Min (Initial) and Max (Final) temperatures shown in the statistics box.
Part A: Find the Heat Capacity of the Calorimeter
- Add 5.0 mL of tap water to the calorimeter. Place a temperature probe through a hole in the calorimeter cover and place the cover on the calorimeter. [Image of coffee cup calorimeter setup]
- Allow the reading to stabilize and record the temperature on your data sheet.
- Place 5.0 mL of tap water in a small beaker and heat the water on a hot plate until the temperature is 15–20 °C above room temperature. Do not heat to boiling. Remove the beaker from the hot plate and allow it to stand for a minute.
- Measure the temperature of this warmed water with a second temperature probe. Allow the reading to stabilize before recording.
- Remove the cover from the calorimeter, quickly pour the warmed water completely into the calorimeter, and quickly replace the cover. Gently swirl while observing the temperature. Record the final stabilized temperature.
Part B: Determine Enthalpy of Neutralization of \(\ce{NaOH}\)–\(\ce{HCl}\)
- Rinse and dry the calorimeter.
- Add 5.0 mL of 1.0 M \(\ce{NaOH}\) to the calorimeter. Measure 5.0 mL of 1.0 M \(\ce{HCl}\) into a dry beaker and allow to stand 3–4 minutes. Measure both temperatures and ensure they differ by less than 0.5 °C.
- When temperatures match, record the initial temperature. Add the \(\ce{HCl}\) to the calorimeter and replace the cover immediately.
- Swirl gently and record the maximum temperature reached.
Part C: Determine Enthalpy of Neutralization of \(\ce{NaOH}\)–\(\ce{CH3CO2H}\)
- Rinse and dry the calorimeter.
- Follow the same procedure as in Part B, substituting 1.0 M \(\ce{CH3CO2H}\) for \(\ce{HCl}\).
- Dispose of any chemical waste according to your instructor.