Thermodynamics problem solve all of the questions (a) to (d) please. thank you.

Question

Thermodynamics problem

solve all of the questions (a) to (d) please. thank you.

Problem 1: Answer the following concept-related questions: (a) When is the energy crossing the boundaries of a closed system heat and when is it work? (b) For a cycle, is the net work necessarily zero? For what kind of systems will this be the (c) If the pressure of a substance is increased during a boiling process, will the temperature also increase or will it remain constant? Why? (d) When pressure and the specific volume of a pure substance (e.g., water) are given, the state of the pure substance can always be determined. Is it true or false? Why?

Explanation / Answer

a. Heat is a form of energy which crosses the boundary of a closed system due to the temperature difference between them .Due to temperature gradient between outside and inside of the boundary of closed system.

Heat and work ate the two forms of energy transfer between a system and its surroundings.

Heat is a non mechanical form of work transfer.

If the energy transfer is not of the form of heat, then it should be work.

work is a mechanical form of energy transfer in which force is acting over a distance

the force is exerted by the system or work done by the external force on the system.

exmple includes the piston and the cylinder, rotating shaft etc.

(b). The net work is not necessarily zero. The net work done is given by W= P.dV

where 'P' is the pressure and 'dv' is the change in volume. For a cycle net work output determines the efficiency of the system and it should be maximum.

Adaibatic system does not allow any heat exchange with the boundary ie, Q= 0. there will be only internal energy variation and it is converted to work.

(c). If the pressure of the system is increased duiring a boiling process, Then the temperature also increases

The boiling point of a substance is the point at which it starts evaporating. so if the ambient pressure is high the molecules of the substance has high resistance to get evaporated into air. Hence the temperature required to boil the substance is high. similarly the boiling point decreases as the pressure comes down to vacuum.

The saturation temperature also increases with increase in temperature due to the boiling process at higher pressure.

(d). when pressure and specific volume of a pure substance is given then the state of the pure substance can be determined is false

because critical temperature , critical pressure and specific volume are the properties required to determine the phases of a pure substance. beccause change in these parameters can change the phase of the system

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