I think it's reactivity. but i'm not sure.
the law of thermodyanamic is the restatement of the law of conservation of energy
<u>Answer:</u> The entropy change of the process is 
<u>Explanation:</u>
To calculate the entropy change for different phase at same temperature, we use the equation:

where,
= Entropy change
n = moles of acetone = 6.3 moles
= enthalpy of fusion = 5.7 kJ/mol = 5700 J/mol (Conversion factor: 1 kJ = 1000 J)
T = temperature of the system = ![-94.7^oC=[273-94.7]=178.3K](https://tex.z-dn.net/?f=-94.7%5EoC%3D%5B273-94.7%5D%3D178.3K)
Putting values in above equation, we get:

Hence, the entropy change of the process is 
<span>Data:
pH = 5.2
[H+] = ?
Knowing that: (</span><span>Equation to find the pH of a solution)</span>
![pH = -log[H+]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH%2B%5D)
<span>
Solving:
</span>
![pH = -log[H+]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH%2B%5D)
![5.2 = - log [H+]](https://tex.z-dn.net/?f=5.2%20%3D%20-%20log%20%5BH%2B%5D)
Knowing that the exponential is the opposite operation of the logarithm, then we have:
![[H+] = 10^{-5.2}](https://tex.z-dn.net/?f=%5BH%2B%5D%20%3D%2010%5E%7B-5.2%7D)