2. Lab Activity Heat Exchange

3. Lab Activity: Heat Exchange • Purpose: • (a) to investigate heat exchange when mixing liquids of different temperatures and verify the formula: -Qloss = Qgain, or -mcΔT(hot) =mcΔT(cold). • (b) to determine the specific heat capacity of an unknown metal, and to use that information to identify the metal. • Materials: • Styrofoam cups, Graduated cylinder, Thermometer, hot water (from a water bath), cold water (from tap). Never leave a thermometer unattended!

4. Procedure (part 1-4) • Place a measured amount of cold water in a Styrofoam cup (measure to 1/10 mL). • Place a measured amount of hot water into water a Styrofoam cup. • Take the temperature of both cups (to 1/10 °C). • Pour the cold water into the hot water. • Stir and take the temperature of the mixture. • Repeat this with four different volume combinations (see suggested volumes) Rewrite these instructions in procedure format

5. Procedure (part 5) • Put about 50 ml (measure an exact amount) of cold water into a Styrofoam cup and measure its temperature. • Take a piece of metal out of boiling water and add it to the cold water (boiling water should be 100°C, but use a thermometer to be sure). • Use the beaker tag to find the mass of metal. • Find the temperature of the water after the metal has been added.

6. Sample Beaker Tagfound at the corner stations for step 5 Metal # Mass of metal Metal #5 Mass = 23.58g ± 0.03g H2O use ≈ 60mL Note: use both pieces! Suggested amount of water to use Other instructions

7. Suggested volumes(do not try to get these exactly. Come close but don’t pour back and forth. Measure to 3 significant digits) If time allows *for water, mass in grams = volume in mL

8. Specific heat capacities of common metals. *Gold, lead, platinum and mercury have similar specific heats, but are easy to tell apart by other properties ** Antimony and Tin are similar, but we don’t use antimony.