Question

Is anyone know how to determine an increasing or decreasing of the entropy (deltaS)?

Answer 1

okay...
entropy refers to randomness, or chaos. When Br2 is a gas, the molecules are more random and chaotic then when they are in the liquid form. Therefore, entropy increases.
Delta S is change in entropy. At its boiling point, the Gibbs free energy of vaporization is zero.
Gibbs free energy, Delta G, is related to Delta S and Delta H.
Delta G = Delta H - T * Delta S
T is the absolute temperature, given in degrees Kelvin.
To find delta H, you have to multiply 29.6 kj/mol by 0.312. 50 grams of Br2 is 0.312 moles of Br2, and each mole of Br2 absorbs 29.6 kj when it vaporizes.
To find T, simply convert C to Kelvins by adding 273.

Answer 2

thanks

Answer 3

Is deltaS has to be increasing at a spontaneous only?

Answer 4

Yes, in our universe entropy is always tending towards a maximum value. For any process to occur in the universe, by definition, it must be spontaneous. It represents an energy change per unit temperature. If there is more energy exchange in a system (the universe), by definition entropy had to increase.