Finding the Specific Heat of a Metal Problem Determine

Finding the Specific Heat of a Metal Problem Determine the specific heat of at least two different metals. Compare your results with the accepted values of these metals, which you can find online Background The specific heat capacity of a material is defined as the heat required to raise a unit mass (1 gram) of the substance by a fixed temperature (1 C). This is sometimes also called the specific heat of a material, and is often abbreviated Cp (which stands for heat Capacity at a constant pressure).

As we have already covered in class, the heat capacity of water is exactly 1 cal/(g C). It takes 1.00 calorie, to raise the temperature of 1.00 gram of water 1.00 oC. This is how the calorie is defined. If needed, you can convert calories to Joules with the conversion factor 1.000 cal 4.184 Joules When a heated metal cube transfers its heat to a sample of water, in a perfectly insulated container, the heat absorbed by the water must be exactly equal to the heat given off by the metal cube. There is a perfect transfer of energy from the cube to the water. q(water) – q(metal). You can use this relationship to determine the heat capacity of a metal. Materials (per group) hot plate 250 or 500 mL glass beaker for heating water metal cube enough water to cover the metal cube when it is placed gently at the bottom of the glass beaker. Styrofoam cup, placed inside a plastic beaker for stability and insulation 100 mL room temperature water in the Styrofoam cup. one or two thermometers. 100 mL volumetric cylinder Tongs. Procedure Measure 100 mL (exactly) of room temperature water in the volumetric cylinder.

Use the known density of water to determine the mass of this water. Pour the water into the Styrofoam cup. Record the temperature of this water at room temperature. This is your starting temperature for the water. Choose one of the metal cubes. Record what type of metal it is (copper, iron, brass, or aluminum). And determine its weight. Place the metal cube carefully in the bottom of the glass beaker. Don’t break the beaker. Fill the beaker with enough tap water to cover the metal cube. Heat the beaker and its contents on the hot plate, until it approaches boiling. Just before taking the metal cube out of the boiling water, measure the temperature of the hot water. You can treat this measurement as the starting temperature of the metal block, since you have no other means to measure the internal temperature of a solid block. Take the metal cube out of the hot water, and transfer it immediately to the foam cup.

Stir the water around the metal cube in the foam cup with the thermometer, until the thermometer reading becomes stable. You can treat this measurement as the final temperature of both the water and the final temperature of the metal block. Choose a second metal cube, and repeat the lab. If you finish early, try a third. Report Go online and find the accepted value for the specific heat of your metals. If the value posted online is not written in the same units you calculated, show the necessary conversions to make it the same units. Calculate the error in your experiment. In a typed paragraph, discuss the possible sources of error in this experiment (focusing especially in issues related to experimental design). Describe practical changes to the experimental design which could correct for these problems. Use vocabulary like heat transfer and specific heat (and related chapter vocabulary) in your discussion to show that you understand their meaning.