A system of four moles of an ideal gas increases its internal energy by 2,992 J as it increases in temperature from 300 K to 360 K. There are no changes in bond energy. Which of the following statements is true? Explain using the appropriate model(s).(a) This gas is monatomic.(b) This gas is diatomic, with its vibrational modes frozen out.(c) This gas is diatomic, with its vibrational modes unfrozen.(d) Not enough information given; you need to know how much work was done on the gas.(e) Not enough information given; you need to know how much heat was transferred to the gas.(f) Both (d) and (e).

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?