Introduction Specific Heat of Metal

Introduction Specific Heat of Metal

Every substance has the ability to absorb and give up heat. A calorimeter is equipment in which heat exchange takes place between 2 fluids that enter and exit at different temperatures. The main function of calorimeter is to either remove heat from a hot fluid or to add heat to the cold fluid. Purpose of this is to use the specific heat of water to calculate heat lost or gained.

Hypothesis

Use the information to determine the object in question. Aluminum is the best choice for now.

Specific Heat Values for Selected Substances

Substance Specific Heat

Cal/g o C J/g oC

Water, H2O (liquid) 1.00 4.18

Iron 0.11 0.46

Copper 0.093 0.39

Aluminum 0.22 0.92

Lead 0.031 0.13

Materials

Materials needed for this are: Thermometer, Bunsen burner, ring stand, iron ring, wire screen, 400-mL beaker, balance or small balance, calorimeter (Styrofoam cup and cover), stirring rod, forceps, and metal object.

Safety

Safety glasses and gloves are worn to prevent injury. Also careful instructions were given before the experiment started.

Procedure:

Start off by filling the 400-mL beaker about two-thirds full of water. Then set up the ring stand with iron ring about 6cm above the top of the Bunsen burner and place the beaker with water on a wire screen. Carefully, light the Bunsen burner and start heating the water in the beaker to boiling point. Then obtain a metal object, record the weight of 10.12g and tie a length of string or fishing line to the metal object. Carefully place the metal object (aluminum, steel, lead, brass) in the boiling water and allow it to boil for 10 minutes. With the metal object in it, the temperature was measured with a thermometer and it was 97oC.

The second step was to weigh a Styrofoam cup, 2.0g, add about 50mL of tap water and weigh it again 51g.The difference was 49g. This is going to be used as the calorimeter. We also got the temperature of that water 20.1oC and recorded the temperature of the tap water. Carefully remove the metal from the hot water bath with forceps and carefully place it in the water in the calorimeter cup as quickly as possible. We close the calorimeter and gently stir the water with the thermometer. We waited for the temperature to peak and record the highest temperature of 23.5oC.

We ended the experiment and remove the metal, dried it off, and started to do the calculation. These are the final reading:

Readings

Mass of metal object: 10.12g Temp of boiling water: 97oC

Mass of Styrofoam calorimeter: 2.0g Temp of water in calorimeter: 20.1oC initial

Mass of Styrofoam calorimeter and water: 51g Temp of water with hot metal: 23.5oC final

Final mass of Styrofoam calorimeter: 49g

Calculations

For the first calculation, the temperature change of the water had to be figured out. The equation is Cal = m x ΔT (oC) x specific heat (1.0). Plugged in the data for each 49g x 3.4oC x 1.0 cal/goC = 166.6cal This is how many heat calories were used to warm water and lost by the metal object.

Next is getting the specific heat for