Answer : The value of change in entropy for freezing process is, -18.07 J/mol.K
Explanation :
Formula used :

where,
= change in entropy
= change in enthalpy of fusion = 3.17 kJ/mol
As we know that:

= freezing point temperature = 
Now put all the given values in the above formula, we get:



Therefore, the value of change in entropy for freezing process is, -18.07 J/mol.K
Answer
Weathering and erosion are two processes of which sedimentary rocks are broken down and carry away existing rocks.
Explanation:
It has to be understood that 2 moles of oxygen are there in each mole of PbO2. Then it has to be calculated for 2 moles of oxygen.
Amount of oxygen = 2 * 5.43 moles
= 10.86 moles
Now it is also a fact that each mole of H2O contains 1 mole of oxygen. Then it can be easily concluded that 10.86 moles of water will be produced. I hope the procedure is clear enough for you to understand.
What I think is the charge of nucleus is the proton+neutron
The Ti 2+ ions is represented by electron configuration (Ar)3d2. Titanium is in atomic number 22 and its electronic configuration is (Ar)3d2 4s2. Titanium loss two electron that is 4s2 electrons hence the electronic configuration ( Ar)3d2. 4s2 is the valence electron hence it the one which is lost to form Ti2+