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Chemistry LibreTexts

Introduction to Calorimetry

  • Page ID
    202236
  • I. Using MicroLab to collect temperature data.

    The MicroLab interface should be set up to collect both Time and Temperature data.

    MicroLab Screenshot showing before any data is taken.
    Once you have set-up the interface, you should have:
    • Time "Sensor" added, on the x-axis, in Column A, and showing in the instant-read area (bottom-right). 
    • Temperature (Thermister) added with the Thermister 103 calibration, on the y-axis, in Column B, and showing in the instant-read area.
    II. Exploring Heat Capacity of Water.

    We want to explore the heat capacity of water and how this affects heat flow while mixing. Typically, cold water from the tap, and hot water from the tap will be sufficient to see a good temperature difference, however, your instructor may wish you to use a hot plate to obtain slightly warmer water. 

    Water being poured into the coffee-cup calorimeter.

    The data below is taken by placing the thermister into the cold water (which is in the beaker), then placing the thermister into the warm water (which is in the coffee cup), and then dumping the cold water into the coffee cup. 

    MicroLab screenshot showing flat line of low temp, flat line of high temp, then coming to equilibrium after mixing.

    Within MicroLab, you can highlight cells within the spreadsheet that correspond to the flat areas. By averaging these values, we can obtain a better measurement of the temperature of the water. Highlight the cells -> right click -> View Column Statistics to view the screen below. 

    Pop-up window screenshot showing column statistics within MicroLab.

    As you can see from the screenshot, over the course of these 30 data points that were highlighted, the average temperature is: 20.2034°C.

    These data analysis techniques will be used in the next experiment, as well. 


    III. Calorimetry of Marshmallows.

    Although we will be burning a marshmallow, not all of it will burn. There will still be some remnants that are not consumed by the flame. Thus: we need to know how much of the marshmallow burned. This involves taking a few different measurements.

    1. Measure the watch glass and the paperclip by itself. 

    Weighing watch glass and paperclip. Balance reads: 87.2571g

    2. Measure the watch glass and the paperclip with the impaled marshmallow.

    Watch glass, paperclip and marshmallow being weighed. Balance reads: 87.9138g.


    3. Perform the experiment, ending with measuring the watch glass, paperclip, and remnants of the marshmallow. 


    Tin can clamped to ring stand with marshmallow on an unfolded paperclip held by hand underneath.
    Initially, the marshmallow is placed on an unfolded paperclip and held directly under the tin can. Note that the tin can is securely placed on the ring stand. The tabletops and ring stand bases are flame-resistant, but try not to test this. Be sure to start the MicroLab a few seconds before igniting the marshmallow to collect initial temperature readings. 

    Close-up of a burning marshmallow
    As the marshmallow begins to burn, the heat rises. Keep it close to the can, but do not smother the flame. 

    Shows marshmallow continuing to burn

    Once the marshmallow finishes burning it is all black.
    Keep the marshmallow there until as long as you can, as heat is still escaping once there is no more flame. Watch your temperature to see it rise. 

    Final shot of experiment with marshmallow resting on watch glass.


    Weighing watch glass, paperclip, and burnt marshmallow. Balance reads: 87.6748g.

    Use the same data analysis techniques described in analyzing the water mixing.