Sobre as Leis da Termodinâmica, são feitas as seguintes afirmações:
I– É possível que um sistema absorva calor e a sua temperatura baixe.
II– Em uma expansão adiabática, para cada unidade de trabalho realizado pelo sistema, a energia interna do sistema aumenta de uma unidade.
III– Em uma expansão isotérmica, a quantidade de calor recebida pelo sistema é igual ao trabalho realizado pelo sistema.
IV– Em um processo cíclico, a energia adicionada ao sistema na forma de calor deve ser igual ao trabalho realizado sobre o sistema durante o ciclo.
V– É impossível transferir energia na forma de calor de um reservatório térmico, à baixa temperatura, para outro com temperatura mais alta.
São verdadeiras apenas as afirmativas
- A) II e V.
- B) II, III e V.
- C) I, III e IV.
- D) I, III e V.
Resposta:
Since this question was annulled and does not have a correct alternative,<|begin_of_text|>201C, I will explain why each statement is true or false.
I - It is possible for a system to absorb heat and its temperature to decrease. This statement is false. According to the laws of thermodynamics, when a system absorbs heat, its internal energy increases, and its temperature rises. The only way for the temperature to decrease is if the system does work on the surroundings or loses heat to the environment.
II - In an adiabatic expansion, for each unit of work done by the system, the internal energy of the system increases by one unit. This statement is true. In an adiabatic process, there is no heat transfer between the system and the surroundings. Therefore, the internal energy of the system increases as the system does work on the surroundings.
III - In an isothermal expansion, the amount of heat received by the system is equal to the work done by the system. This statement is true. In an isothermal process, the temperature remains constant, and the internal energy of the system does not change. Therefore, the heat absorbed by the system is equal to the work done by the system.
IV - In a cyclic process, the energy added to the system in the form of heat is equal to the work done on the system during the cycle. This statement is true. In a cyclic process, the initial and final states of the system are the same. Therefore, the energy added to the system in the form of heat is equal to the work done on the system during the cycle.
V - It is impossible to transfer energy in the form of heat from a thermal reservoir at a lower temperature to another at a higher temperature. This statement is true. This is a fundamental principle of thermodynamics, known as the second law of thermodynamics. It states that heat cannot spontaneously flow from a colder body to a hotter body.
Therefore, statements II, III, IV, and V are true, while statement I is false.
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