Question

One mole of H2O(l) is compressed from a state described by P =1.00 bar and T = 350. K to a state described by 515 bar and 795 K . In addition, β=2.07×10−4K−1 and the density can be assumed to be constant at the value 997 kgm−3 .

Calculate ΔS for this transformation, assuming that κ = 0.

Answer 1

Solution:

1 mole H₂O is compressed from 1 bar and 350 K to 515 bar and 795 K

Vollume of the sysyem remains constant.

First we will calculate Volume occupied by sysyem,

1 mole H₂0 = 18 Kg of H₂O

Therefore, V = Mass/Density

= 18/997

= 0.01805 m³

we know the formula for

= Q_system/T

Q = VP

= 0.01805 * (51500 - 100)....................Convert bar to Kpa because Kpa*m³ = KJ

= 927.77 KJ

Now,

S = 927/(795-350)

= 927/445

= 2.083 KJ/KmolK.................................. Final answer