1 Nitrogen is contained in a 4 m3 rigid tank at 350 K and 12

1) Nitrogen is contained in a 4 m3 rigid tank at 350 K and 12 bar. If the tank is left outside in the sun, which results in a net heat transfer of 2000 kJ to the tank, what is the final temperature and pressure?

2) A rigid copper tank contains liquid water as shown in the figure. The mass of the copper is 20 kg and its initial temperature is 32.0C. The mass of the water is 6 kg and its initial temperature is 55.0C. An electrical resistor transfers 200. kJ of energy to the system. Calculate the final temperature of the system.

Solution

For the second problem, there is no image given and please post one more question to get the answer to the second problem, i have solved the first problem in detail

1) Using the ideal gas equation

PV = nRT

(12 bar * 0.986923 atm/1 bar) * (4m^3 * 1000L/1m^3) = n * 0.0821 * 350

n = 1648.592 moles of N2 gas

specific heat capacity of N2 = 1.041 g/C at 350K

Mass of N2 gas = 1648.592 moles * 28 gm/mol = 46160.588 grams

2000 * 10^3 = mass of N2 * specific heat of N2 * (change in temperature)

2000 * 10^3 = 46160.588 * 1.041 * (change in temperature)

change in temperature = 41.62

Final temperature = 41.62 + 350 = 391.62

Using the ideal gas equation again

PV = nRT

since volume remains constant because the tank is rigid

P1/T1 = P2/T2

P2 = 12 bar * 391.62/350 = 13.426 bar