Aturbine operates on superheated steam that enters at 80 bar absolute and 500˚c, and leaves the turbine at 7.5 bar absolute and 250˚c. the flow rate of the steam is 400 kg/min and the turbine operates adiabatically. the steam exiting the turbine goes to a heater, which is supplied with 2000
2kw of energy. the steam leaves the heater at 5 bar absolute. all of the pipes through which the
steam flows are 0.5 m (id) in diameter.
a. how much power is produced by the turbine? (4 marks)
b. what is the temperature of the steam leaving the heater? (4 marks)
c. what is the velocity (m/s) of the steam entering the turbine? (3 marks)
d. to what temperature can the steam at 80 bar be cooled before a liquid will appear?

what is the volume occupied by 40 grams of argon gas (ar) at standard conditions? what volume, in liters, is occupied by 1.5 x 1023 

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.