ir at 3 bar and 25°C expands to 1 bar and 25°C by the following mechanically-reversible process:heated at constant pressure followed by cooling at constant volume. Calculate the heat andwork requirements and ∆U and ∆H of the air for this path. For air assume the following heat capacities(independent of temperature):CV= 20.785 J mol−1K−1and CP= 29.1 J mol−1K−1. Also assume that the air remains a gas with PV/T=constant, at 1 barand 25°C the molar volume of the air is ̄V= 0.02479m3mol−1

Stefan-Boltzman law which describes the radiation heat transfer states that, it is proportional to (where, t = temperature in °C T = absolute temperature in °K) A. +4 T4 B. C. D. O 1 t4 1 T4

Question 1.2 A helical coil cooler is used to cool 0.5 kg.s¹ of hot oil from 100°C down to 40°C. Cooling water with an inlet temperature of 10°C flows inside the coiled tube. The specific heat of the oil is 2 kJ.kg¹.K¹, the specific heat of the water is 4.2 kJ.kg¹.K¹, and the density of water is 1000 kg.m. a) Determine the lowest possible cooling water flow rate. (0.48 kg.s¹) b) Determine the inside diameter of the tube if a cooling water flow of 1.5 times the minimum is used, and the recommended flow velocity is 1 m.s. Select an appropriate tube from the following standard sizes: Outside diameter (mm) Wall thickness (mm) 30 1.5 35 2.0 40 2.0 45 2.5 50 3.0 c) For a heat transfer coefficient of U = 800 W.m2.K, determine the heat transfer surface area and the tube length of the heat exchanger. The oil inside the tank is mixed by a stirrer and the oil temperature at any location in the tank can be assumed to be equal to the oil outlet temperature. (Area = 4.12 m², length = 39.7 m)

1.7 moles of water are placed inside a sealed container and its temperature is initially 70 ̊C. The container, which allows heat to transfer, is placed inside a very large acetone/dry ice bath at -77 ̊ C for a sufficiently long time to allow the water to cool to 20 ̊C. The specific heat of water is 4.184 J/gK. Find ∆Ssys, ∆Ssurr, and ∆Suni for this process.