Chemistry 1515L Week 12
Graduate Teaching Assistant
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SPECIFIC HEAT OF A METAL
SPECIFIC HEAT
is the amount of energy required to raise the temperature of 1 gram of a substance by 1 degree Celcius (or Kelvin)
Examples of Specific Heat values:
Metals have low Specific Heat values, for example:
For iron (Fe):
SH = 0.45 J/g ∙ °C (at 25 °C)
Water has a higher Specific Heat value:
Water has a higher Specific Heat value:
For H2O: SH = 4.18 J/g ∙ °C (at 25 °C)
Today you will find Specific Heat values for samples experimentally 1
SPECIFIC HEAT OF A METAL
In this experiment you will:
1. Heat a piece of an unknown metal in boiling water
2. The you transfer that hot metal to a known amount of water
3. You measure the rise in temperature of the water as the energy is transferred from the metal to the water
4. You then use the temperature difference to calculate the Specific Heat (S) of the metal using the following equation:
(Smetal)(g of metal)(Tf‐Ti)metal = ‐[(Swater)g of water)(Tf‐Ti)water + Ccal(Tf‐Ti)cal]
Given: Swater = 4.18 J/g ∙ °C
Ccal (heat Capacity of cup) = 42 J/°C You will find the values for Tf‐Ti experimentally
SPECIFIC HEAT OF A METAL
The instructions for this experiment are slightly different to those
found in the lab manual and modified instructions are provided on
the 1515L web page:
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SPECIFIC HEAT OF A METAL
We will use a THERMOCOUPLE connected to the MicroLab box in order to measure temperature changes accurately:
The thermocouple is sensitive so don’t move it around when you are collecting data. SPECIFIC HEAT OF A METAL
The thermocouple needs to be calibrated initially using boiling water
(100 °C) and ice water (0 °C). Detailed instructions are on the 1515L web
page:
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SPECIFIC HEAT OF A METAL
The instructions contain lots of detail on how this experiment works so follow them carefully. SPECIFIC HEAT OF A METAL
Once you have the thermocouple calibrated, the experiment itself
is quite straightforward. You do two different metals.
Styrofoam coffee cup used as a calorimeter
Note: You do not have to press STOP in between experiments
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For Next Lab Session:
• Read all of the material available (Lab Manual and Website) related to the next experiment (Enthalphy Change)
• Email me with any concerns.
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