Read the following reactions. Reaction 1: NaCl(s) -> Na+ (aq) + CI-
Reaction 2: N2 + 3H2 -> 2NH3

Which reaction leads to an increase in entropy?

Only Reaction 1
Only Reaction 2
Both Reaction 1 and 2
Neither Reaction 1 nor 2
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Only Reaction 1

Explanation:

In reaction 1, there is a change in state from solid to liquid. Hence, there is an increase in number of ways particles and their energies could be arranged. As a result, entropy increases.

In reaction 2, there is a decrease in amount of gas particles (4 mol to 2 mol). Hence there is a decrease in the number of ways particles and their energies could be arranged. As a result entropy decreases

the electronic configuration of an atom with eight electrons is 1s²2s²2p⁴. the orbital diagrams are shown in the figure.

as per the hunds rule:

1. electrons tend to avoid being in the same orbital as per as practicable.

2. electrons in different orbitals of the same energy will have their spin parallel.

this can be illustrated from the multiplicity of the orbitals of the atom. as there are four electrons in the p orbital and p orbital has 3 sub-shells. the electrons can be fed in different ways as shown in the figure but the correct orbital diagram will be as per the hunds rule.