ENEM PPL 2020 - Tanto a conservação de materiais biológicos como o resfriamento de certos

🔥 Join the largest and best educational platform for getting into medical school through ENEM and other entrance exams. 👇🏼 https://plataformaviniciusoliveira.co... 📸 Social media:   / viniciusdeoliiveira   📚 ENEM PPL 2020 - Both the preservation of biological materials and the cooling of certain photodetectors require low temperatures that are not easily achieved by refrigerators. A common practice to achieve these temperatures is the use of liquid nitrogen, obtained by the adiabatic expansion of N2 gas, contained in a container coupled to a piston, resulting in cooling to temperatures that reach its liquefaction point at −196 °C. The figure shows a sketch of pressure curves as a function of the volume occupied by a quantity of gas for isothermal and adiabatic processes. The differences between these processes can be identified based on the first law of thermodynamics, which associates the change in internal energy with the difference between the heat exchanged with the external environment and the work done in the process. Adiabatic expansion enables the cooling of N2 because: A) the heat input that occurs during expansion due to work contributes to the decrease in temperature. B) the heat output that occurs during expansion due to work contributes to the decrease in temperature. C) the change in internal energy is zero and the work is directly associated with the heat flow, which decreases the temperature of the system. D) the change in internal energy is zero and the work is directly associated with the cold input, which decreases the temperature of the system. E) the work is directly associated with the change in internal energy and there is no heat exchange between the gas and the environment. ✅ Question number in the exam booklets: Question 113 of the ENEM PPL 2020 in the yellow booklet; Question 126 of the ENEM PPL 2020 in the pink booklet; Question 114 of the ENEM PPL 2020 in the gray booklet; Question 110 of the ENEM PPL 2020 in the blue booklet.