<h3><u>Answer;</u></h3>
CO3^2- and O3
<h3><u>Explanation;</u></h3>
- Ozone, O3 is a molecule composed of three oxygen atoms joined together. Two oxygen atoms joined together form the basic oxygen molecule O2.
- A polyatomic ion is a charged particle which has two or more atoms held together by covalent (sharing of pairs of electrons) bonds.
- Carbonate (CO3^2-) is an example of polyatomic ion. It can not be adequately described using Lewis structure.
The main purpose of scientific methods, is to show the variations of the topic you are doing in science and how you are proving it to be that way.
Answer:
I think it's D one. Because all others are wrong
Answer: NaCl (s) → NaCl (aq)
Explanation:
Entropy is often associated with the disorder or randomness of a system. Therefore, in each reaction, it is necessary to evaluate if the disorder increases or decreases to understand what happens to the entropy:
1) KCl (aq) + AgNO₃ (aq) → KNO₃ (aq) + AgCl (s) - In this reaction, we have only aqueous reactants in the beginning and in the product we have a precipitate. The solid state is more organised than the liquid, consequently, the entropy decreases.
2) NaCl (s) → NaCl (aq) - In this case, oposite to the first one, we go from a solid state to an aqueous state. The solvation of the ions Na⁺ and Cl⁻ is random while the solid state is very organised. Therefore, in this reaction the entropy increases.
3) 2NaOH (aq) + CO₂ (g) → Na₂CO₃ (aq) + H₂O (l) - In this reaction, the reactants have higher entropy because of the gas CO₂. Therefore, the entropy decreases.
4) C₂H₅OH (g) → C₂H₅OH (l) - In this reaction, the reactant is a gas and the product a liquid. Therefore, the entropy decreases.
