Choose the substance with the higher entropy in each pair. Assume constant temperature, except in part (5) (i) 1 mol of SO2(g) or 1 mol of SO3(g)
(ii) 1 mol of CO2(s) or 1 mol of CO2(g)
(iii) 3 mol of O2(g) or 2 mol of O3(g)
(iv) 1 mol of KBr(s) or 1 mol of KBr(aq)
(v) Seawater at 2°C or at 23°C
(vi) 1 mol of CF4(g) or 1 mol of CCl4(g)

I) 1 mol of SO3(g)

2) 1 mol of CO2(g)

3) 3 mol of O2(g)

4) 1 mol of KBr(aq)

5) Seawater at 23°C

6) 1 mol of CCl4(g)

Explanation:

In molecules having greater numbers of atoms, there is an increase the number of ways by which the molecule vibrates thereby leading to a higher number of possible microstates and overall increase in entropy of the system. Hence, 1 mol of SO3(g) has a higher entropy than 1 mol of SO2.

Gases have a higher entropy than liquids and liquids have a higher entropy than gases.

Also, the greater the molecular weight of a molecule, the higher the entropy. Higher number of moles of a gas as well as the increase in temperature of a substance are also factors that lead to higher entropy.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%