Given:
AgCl (s) ===> Ag+ (aq) + Cl- (aq)
- negative entropy
H2O(g) ===> H2O(l)
- positive entropy
2Na (s) + Cl2 (g) ===> 2NaCl (s)
- positive entropy
Br2(l) ===> Br2 (s)
-positive entropy
They are identified to have positive or negative values of entropy based on the phases of the reactants and products.
"For example; water is a covalent compound which is formed by the covalent bonding between hydrogen and oxygen atoms."
Answer:

Explanation:
We will need a balanced chemical equation with masses, moles, and molar masses.
1. Gather all the information in one place:
Mᵣ: 18.02
2Na + H₂O ⟶ 2NaOH + H₂
m/g: 72.0
2. Moles of H₂O

3. Moles of Na
The molar ratio is 2 mol Na/1 mol H₂O.
