How many calories are needed to raise 500 grams of water from 25 degrees Celsius

Question

1. How many calories are needed to raise 500 grams of water from 25 degrees Celsius to 40 degrees Celsius?

2. Define the following terms:
   1. Internal energy
   2. Specific heat
   3. Entropy
   4. Temperature

3. 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?

4. 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.

5. State and explain the first and second laws of thermodynamics.

6. Calculate the change in internal energy for each of the following systems:
   1. 100 joules of energy is added to a system that does 40 joules of external work.
   2. 75 joules of energy is removed from a system that has 50 joules of work done on it.
   3. 150 joules of energy is added to a system that has 75 joules of work done on it.

7. Explain why a body of water freezes from the top down rather than from the bottom up.

Explanation / Answer

1) It takes one calorie to raise one gram of water one degree centigrade

So 40 - 25 = 15 degrees x 500 grams = 7500 calories

2) 1)the energy in a system arising from the relative positions and interactions of its parts.

2)the heat required to raise the temperature of one gram of a substance one degree centigrade

3)a thermodynamic quantity representing the unavailability of a system's thermal energy for conversion into mechanical work, often interpreted as the degree of disorder or randomness in the system

4) the degree or intensity of heat present in a substance or object, especially as expressed according to a comparative scale and shown by a thermometer or perceived by touch.

3) If a 1-meter bar expands 0.5 cm, the expansion is 0.5 cm per meter. If a 100-m bar of the same material is heated, the expansion will be 100 m

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.