Hi, I'm in my last year of industrial engineering and I have an exam on monday for which I need your help in answering some exam questions. It's a lot of questions but any answer is appreciated. Here they come:

1) 3kg of air (2 bar, -10°C) is being adiabatically compressed to 200°C after which an isobare cooling halves the volume. Then 300kJ of heat is drained at a constant volume. Through a polytropic expansion the starting condition is reached. Calculate: coldness factor, Q1 and Q2.

2) Take the system below: ideally isolated compared to the environment, the sucker can move frictionless and is an ideal heat isolator.
How long does the electric resistance of 500W have to be enabled in order to reach an ending pressure of 4 bar? Point out the change of state of the steam and air on the Ts diagram.
Note: The attached document contains the figure with this question.

3) Calculate delta s between saturated steam of 12 bar and wet steam of 40 bar, with x = 0.8. Draw the start and end state in a T-s and h-s diagram.
(Answer: delta s = -1.105kJ/kg.K)

4) Calculate delta s between water of 50°C and overheated steam of 12 bar and 250°C.
(Answer: delta s = 6.141kJ/kg.K)

5) How many degrees Kelvin does steam of 50 bar have to be overheated in order to obtain an isentropic expansion up to 5 bar of saturated steam?
(Answer: delta T = 186 K)

6) Calculate delta H when 1 m³ of steam (10 bar, 200°C) reversibly expands to 5 bar.
a. adiabatic
b. isothermic
Draw the processes in a T-s and h-s diagram.
(Answer: a. -634kJ, b. 137kJ)

7) What is the entropy increase at an isobare heating of 2kg of air, from 0°C to 100°C.
(Answer: delta S = 627.3J/K)

8) In a gas turbine, air (400°C, 20 bar) expands at 1200 m³ (NTP) per hour reversibly adiabatic to 1 bar.
Calculate the work per m³ (NTP) and the capacity.
(Answer: L = 5.02*10^5 J/m³, P = 169kW)

9) A saturated liquid R134a of 30°C is being smoked in a smoke valve of a cooling machine until a temperature of -35°C is reached.
Calculate the vapour amount at the end state.
(Answer: x = 0.39)

10) In a radiation tube air expands irreversably adiabatic from 7 bar to 1 bar. The starting speed is 60m/s, the starting temperature is 360°C. The internal gain is 85%. Calculate the ending speed of the air and the ending temperature.
(Answer: c_2 = 682m/s, T_2 = 403K)

11) In a compressor, 10m³ of air (20°C, 1 bar) per minute is being isothermically compressed to 8 bar. n_i (internal gain) = 0.85. Calculate the capacity.
(Answer: P_i = 40.8kW)

12) 1kg of water (30 bar, 40°C) is being heated isobaric. 3MJ of heat is being added. Calculate the ending temperature.
(Answer: t_2 = 372°C)

13) 1kg of steam (0.2 bar, x = 0.8)is being cooled isobaric to 40°C. Calculate the drained heat.
(Answer: Q = 1971kJ)

14) 3kg of liquid R134a (14 bar, 30°C) undergoes an isentropic expansion to a pressure of 4.884 bar. Calculate the enthalpy of the ending state.
(Answer: H = 721.4kJ)

15) Steam (400°C, 6 bar) undergoes an isentropic expansion in a turbine to 1 bar. Calculate the turbine's work per kg of steam.
(Answer: l = 456kJ/kg)

16) 4kg of water (4 bar, 80°C) is being adiabatically mixed with 1kg of steam (4 bar, 250°C). Calculate the ending temperature.
(Answer: T_2 = 143.6°C)