* Со x B-A 0.02% C steel is to be carburized at 1200°C in 4 h, with a point 0.6 mm beneath the surface reaching 0.45% C. Calculate the carbon content required at the surface of the steel. Do-0.23 cm² /s, Q-32900 cal/mol. CA Do Values

1. Two moles of helium gas are placed in a cylindrical container with a piston. The gas is at room temperature 27 °C and under a pressure of 3.3.105 Pa. When the pressure from the outside is decreased, while keeping the temperature the same as the room temperature, the volume of the gas doubles. Use that the gas constant R = 8.31 J/(mol K). Think: What kind of process is this? Isobaric, isothermal, adiabatic, isochoric or non-quasi-static? (a) Find the work the external agent does on the gas in the process. W = ext. agent (b) Find the heat exchanged by the gas and indicate whether the gas takes in or gives up heat. Assume ideal gas behavior. Q= ✓J Q is realeased by gas Q is absorbed by the gas

Problem 6:  Suppose you pour 0.0125 kg of 20.0°C water onto a 1.1-kg block of ice, sitting in a large bowl, which is initially at -15.0°C. The latent heat of fusion for water is Lf = 334 kJ/kg.   What is the final temperature of this system? You may assume that the water cools so rapidly that effects of the surroundings are negligible.

22. CD A tank contains 0.85 mol of molecular nitrogen (N,). Determine the mass (in grams) of nitrogen that must be removed from the tank in order to lower the pressure from 38 to 25 atm. Assume that the volume and temperature of the nitrogen in the tank do not change.