Question

Four kilograms of carbon monoxide (CO) is contained in a rigid tank with a volume of 1 m3 . The tank is fitted with a paddle wheel that transfers energy to the CO at a constant rate of 14 W for 1 h. During the process, the specific internal energy of the carbon monoxide increases by 10 kJ/kg. If no overall changes in kinetic and potential energy occur, determine (a) the specific volume at the final state, in m3 /kg. (b) the energy transfer by work, in kJ. (c) the energy transfer by heat transfer, in kJ, and the direction of the heat transfer.

Answer 1

Answer:

a)$v= 0.25 \ m^3/kg$

b)W= 50.4 KJ

c)Q= -10.4 KJ

It means that heat will be rejected from the system.

Explanation:

m= 4 kg

$V=1 \m^3$

Work in put = 14 W  14 J/s

1 h = 60 sec

Work in put = 14 x 60 J

W=14 x 60 J =840 J

ΔU= 10 KJ/Kg

ΔU= 10 x 4 = 40 J

a)

We know that specific volume is the ratio of volume and mass.

v= V/m

$v= 1/4 = 0.25 \ m^3/kg$

b)

Energy transfer by  work =W

W=14 x 60 x 60 J =50.4  KJ

W= 50.4 KJ

c)

From first law of thermodynamics

Q = ΔU + W

Here work in added to the system that is why W= -840 J

Q = 40 - 50.4 KJ

Q= 40 - 50.4  KJ

Q= -10.4 KJ

It means that heat will be rejected from the system.