For the following processes, calculate the indicated quantities for a system consisting of 1 mol of N 2 gas. Assume ideal gas behavior. a. The gas, initially at 10 bar, is expanded tenfold in volume against a constant external pressure of 1 bar, all at 298 K. Calculate q, w, !U and !H for the gas. b. After the expansion in part (a), the volume is fixed, and heat is added until the temperature reaches 373 K. Calculate q, w, !U and !H. c. What will be the pressure of the gas at the end of the process in part (b)? d. If the gas at 373 K is next allowed to expand against 1 bar pressure under adiabatic conditions (no heat transferred), will the final temperature be higher, remain unchanged, or be lower than 373 K? Explain your answer.

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?

Which bonds are found inside a water molecule