2.19 for a k+−cl− ion pair, attractive and repulsive energies ea and er, respectively, depend on the distance between the ions r, according to e a = − 1.436 r e r = 5.86 × 10 − 6 r 9 ea=−1.436rer=5.86×10−6r9 for these expressions, energies are expressed in electron volts per k+−cl− pair, and r is the distance in nanometers. the net energy en is just the sum of the preceding two expressions. (a) superimpose on a single plot en, er, and ea versus r up to 1.0 nm. (b) on the basis of this plot, determine (i) the equilibrium spacing r0 between the k+ and cl− ions, and (ii) the magnitude of the bonding energy e0 between the two ions.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Which of the following refers to refers to how well the control system responds to sudden changes in the system. a)-transient regulation b)- distributed regulation c)-constant regulation d)-steady-state regulation

A2-m rigid tank initially contains saturated water vapor at 100 kpa. the tank is connected to a supply line through a valve. steam is flowing in the supply line at 600 kpa and 300 c. the valve is opened, and steam is allowed to enter the tank until the pressure in the tank reaches the line pressure, at which point the valve is closed. a thermometer placed in the tank indicates that the temperature at the final state is 200°c. determine (a) the mass of steam that has entered the tank (b) the amount of heat transfer.