Lab 40: Calorimetry
Calorimetry is the measurement of the quantity of heat exchanged during chemical reactions or physical changes. For example, if the energy from an exothermic chemical reaction is absorbed in a container of water, the change in temperature of the water provides a measure of the amount of heat added.
Calorimetry involves the use of a calorimeter. In this activity you will learn how the energy change in a physical change can be measured using a calorimeter.
• Heat is the flow of energy associated with the random motion of particles (temperature). • The unit for Heat Energy is the Joule (J). • Kinetic Energy is the energy associated with the motion of atoms and molecules. • Temperature is a measure of the kinetic energy in a sample of material. • The symbol ΔT refers to “the change in temperature.” Example: ΔT = 5.00 0C means a temperature change of 5 0C (Tfinal – Tinitial). • Heat Capacity is the energy required to raise the temperature of a 1 g sample of a substance 1 0C (or 1 Kelvin degree). • The specific heat capacity for water is 4.18 Joule/gram Kelvin degree
Safety
• Tie your hair back
• Wear goggles
• Don’t throw matches in the sink
• Glassware can break when rapidly cooled or heated
• Hot glassware can cause burns
Materials
• Apron
• 250-mL Beaker
• Bunsen Burner
• Calorimeter
• Goggles
• Graduated cylinder
• Matches
• Metal
• Ring stand
• Ring
• Water
• Wire gauze
• Tongs
• Thermometer
Methods
1. Find the mass of the metal provided by the teacher.
2. Place 75.0 mL of water into the middle cup of your calorimeter.
3. Heat about 100 mL of water in your 250-mL beaker with the Bunsen burner. Measure the temperature of the water. After the water reaches around 100 degrees, place your metal substance into the beaker and