Lab 7 – Heat and Temperature
• Observe the first law of thermodynamics: that energy is conserved.
• Investigate the transfer of heat.
• Determine the heat of fusion of ice
• Determine the heat of neutralization of acids and bases.
1. Heat is another form of energy, and can be quantified with familiar units, joules.
2. The transfer of heat can be calculated by measuring a change in the temperature,
3. The heat capacity of a material tells you how much heat energy is required to cause a change in temperature. The heat capacity depends on how much the
material there is and is therefore referred to as the specific heat capacity.
Some specific heat capacities of materials:
water has a relatively high specific heat (4.184 J/°C*gram)
copper has a relatively low specific heat (0.378 J/°C *gram)
****To raise the temperature of water by 1 °C would take more than 11× the energy required to raise the temperature of the same mass of copper by 1 °C.
4. A calorie is the amount of heat required to raise the temperature of 1 gram of water by 1°C. The specific heat of water is equal to 1 calorie/°C*gram.
****We will make volumetric measurements using graduated cylinders, so the effective heat capacity for all our experiments is 1 calorie/°C*mL. (density of water is 1g/mL)
5. Heat of fusion – how much heat is required to melt ice; therefore the heat absorbed for the action of melting an amount of ice. (calories/gram)
6. Heat of neutralization – amount of heat given off in the reaction of an acid with a base.
HCl (aq) + NaOH (aq) Æ NaCl (aq) + H2O (l) + heat