Skip to main content
Chemistry LibreTexts

1.12: Experiment 10 - Calorimetry

  • Page ID
    291231
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    Learning Objectives

    By the end of this lab, students should be able to:

    • Design an experiment to determine the calorimeter constant.
    • Predict factors that might influence your experimental results, and how to minimize error.
    • Correlate variability in data to limitations in the physical set up of our lab.

    Prior knowledge:

    Introduction

    Calorimetry is the science of measuring heat flow. Heat is defined as thermal energy flowing from an object at a higher temperature to one at a lower temperature. For example, if you drop a coin into a cup with hot water, the temperature of the coin will go up until it is at the same temperature as the boiling water. This will happen because the coin will be absorbing the heat from the water. 

    Calorimetry is based on the First Law of Thermodynamics that states that energy cannot be created nor destroyed. The heat of neutralization that is lost in the chemical reaction (the system) is gained by the calorimeter and its contents (the surroundings).

    Pre-Lab Primer

    This pre-lab assignment is an individual assignment to be completed on your own with the help of the links in the document and at the top of this page. All work must be in your own words. Do not copy and paste information from the internet. The assignment will be due 10 minutes before your lab begins. Late work will not be accepted.

    The document below is a preview only. Please do not try to screenshot or print it off. You will be able to find your assignment to work on in your Google Classroom.

    Interactive Element

     

    In-Lab Assignment

    Group Assignment

    In the ideal world, we would have a calorimeter that is so well insulated, that all of the heat gained or lost during the reaction is contained inside the calorimeter completely. You can read more about the heat transfer in an ideal calorimeter here. In reality some of it "escapes", since the calorimeter we have isn't a perfect insulator. Our calorimeter will absorb and lose heat. Keep that in mind when you are doing your worksheet. 

    To make sure you get accurate results you need to calculate the calorimeter constant, which is the calorimeter's heat capacitance. We use capital \(C\) to represent the heat capacitance of an object, so for the calorimeter constant we will use \(C_{cal}\). Calorimeter constant has to be measured for every calorimeter and this is going to be the first part of this lab. 

    If we look at the equation \(q_{C} = - \;q_{H}\) and apply it to our real calorimeter we will see, that there are two cold objects that contribute to \(q_{C}\) - the cold substance and the calorimeter itself. This means that

    \[q_{C}\;= \left( \;m_{C}\;\times \;c_{C}\;\times \;\Delta T_{C}\; \right) + \left( \;C_{cal}\;\times \;\Delta T_{C} \right) \]

    Using Zoom Breakout rooms, you will work collaboratively with your group on a Google Doc worksheet called "Group Calorimeter Constant Worksheet". Each person can type in this document at the same time. Remember, part of your grade comes from your participation during lab, so there will be a Peer Evaluation this week. Make sure you are contributing to discussion and to the completion of the worksheet. The worksheet will be due by the end of your lab session, and late work is not accepted. Be sure to turn your assignment in on Google Classroom.

    The document below is a preview only. Please do not try to screenshot or print it off. You will be able to find your assignment to work on in your Google Classroom.

    Interactive Element

     

    Contributors and Attributions 

    • Robert E. Belford (University of Arkansas Little Rock; Department of Chemistry) led the creation of this page for a 5 week summer course. 

    • Elena Lisitsyna contributed to the creation and implementation of this page.

    • Mark Baillie coordinated the modifications of this activity for implementation in a 15 week fall course, with the help of Elena Lisitsyna and Karie Sanford.

    1.12: Experiment 10 - Calorimetry is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.