Chapter 16, Problem 4STP

Interpretation Introduction

Interpretation:

The change in potential energy and kinetic energy from point C to point D in the given curve needs to be explained.

Concept introduction:

The conversion of solid to liquid and gas involves the change in temperature that can display in heat curve.

The heating -cooling curve is the curve of temperature v/s time that interpret the change in the states of matter with increase in temperature. The phase diagram represents the change in the physical state of given substance with temperature and pressure.

Answer to Problem 4STP

Correct answer: Option C is correct answer.

Explanation of Solution

Reason for correct option:

The point A indicates the solid state and at B it should start melting as there is a deflection point at B. The BC segment does not have any temperature change with time. It proves that the given energy is used to change the state of matter from solid to liquid that is called as melting. Thus the segment BC must show the melting. After BC segment, from point C to D, it remains in liquid state. In liquid state the potential energy remains constant whereas kinetic energy of substance increases due to increase in the temperature of the substance.

Conclusion

Reasons for incorrect options: When a substance is heated, the potential energy remains constant whereas kinetic energy increases due to increase in temperature.