Question

1. Define the following terms:

   1. Internal energy

   2. Specific heat

   3. Entropy

   4. Temperature

2. Suppose a 1 meter long bar expands 0.5 centimeters when heated. By how much will a 100 meter long bar of the same material expand when similarly heated?

3. State how much energy is transferred in each of the following cases:

   1. 2 grams of steam at 100 degrees Celsius condenses to water at 100 degrees Celsius.

   2. 2 grams of boiling water at 100 degrees Celsius cools to ice water at 0 degrees Celsius.

   3. 2 grams of ice water at 0 degrees Celsius freezes to ice at 0 degrees Celsius.

   4. 2 grams of steam at 100 degrees Celsius turns to ice at 0 degrees Celsius.

Answer 1

1. a) Internal energy is defined as the total energy within a system. Introduction of matter & heat increases internal energy of a system.

b) Specific heat capacity is defined as the amount of heat required to be supplied to a system to cause a unit change in temperature.

c) Degree of disorder or randomness in a system is defined as entropy. Physically it is defined as the amount of energy that is unavailable to be converted to work.

d) Temperature is a physical quantity that represents hotness or cold. In terms of thermodynamics, the measure of average kinetic energy of atoms and molecules is denoted as temperature.