Ch3sh is polar because it has polar bonds & the net dipole is nonzero
<u>Answer:</u> When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.
<u>Explanation:</u>
Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.
According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.
The overall chemical reaction follows:

The intermediate balanced chemical reaction are:
(1)
(2)

The expression for enthalpy of the reaction follows:
![\Delta H^o_{rxn}=[1\times (\Delta H_1)]+[\frac{1}{2}\times (-\Delta H_2)]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B1%5Ctimes%20%28%5CDelta%20H_1%29%5D%2B%5B%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%28-%5CDelta%20H_2%29%5D)
Hence, when the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.
Explanation
NaCl: Ionic crystal lattice forces
Hg: Metallic bonding
CO₂: London dispersion forces
CH₄: London dispersion forces
Li₂O: Ionic crystal lattice forces
Ag: Metallic bonds
Ionic crystal lattice forces are strong electrostatic force of attraction between oppositely charged ions arranged into a crystal lattice of ionic compound. NaCl and Li₂O are ionic compounds
London dispersion forces holds the molecules of carbon dioxide and methane. They are weak attractions found between non-polar (and polar) molecules.
Metallic bonds exists between Mercury and Gold atoms. This is due to sea of electrons present.