Which species are more resonance stabilized in the following pairs:
`[C_(6)H_(5)Cl, C_(6)H_(5)CH_(3)], [CH_(2)=CHCl, CH_(2)=CHCH_(2)Cl]`,
`[C_(6)H_(5)Br, C_(6)H_(5)CH_(2)Br], [CH_(3)COOH, CH_(3)COO^(-)]`

Options

A. `C_(6)H_(5)Cl, CH_(2)=CHCH_(2)Cl, C_(6)H_(5)CH_(2)Br, CH_(3)COO^(-)`
B. `C_(6)H_(5)CH_(3), CH_(2)=CHCH_(2)Cl, C_(6)H_(5)CH_(2)Br, CH_(3)COO^(-)`
C. `C_(6)H_(5)C1, CH_(2)=CHCl, C_(6)H_(5)Br, CH_(3)COOH`
D. `C_(6)H_(5)Cl, CH_(2)=CHCl, C_(6)H_(5)Br, CH_(3)COO^(-)`

Explanation

To determine which species are more resonance stabilized in the given pairs, we will analyze each pair one by one, focusing on the ability of each species to delocalize electrons through resonance.

### Step-by-Step Solution:

1. **Pair 1: [C6H5Cl, C6H5CH3]**
- **C6H5Cl (Chlorobenzene)**: The chlorine atom has a lone pair that can participate in resonance with the benzene ring. This allows for the delocalization of electrons, creating resonance structures that stabilize the molecule.
- **C6H5CH3 (Toluene)**: The methyl group (CH3) does not have a lone pair and does not participate in resonance. It can only exert an inductive effect, which is less stabilizing compared to resonance.
- **Conclusion**: C6H5Cl is more resonance stabilized than C6H5CH3.

2. **Pair 2: [CH2=CHCl, CH2=CHCH2Cl]**
- **CH2=CHCl (Vinyl chloride)**: The chlorine atom can participate in resonance with the double bond, allowing for some delocalization of electrons.
- **CH2=CHCH2Cl (Allyl chloride)**: In this case, the chlorine atom is attached to a carbon that is part of a longer chain. The double bond can still participate in resonance, but the resonance is less effective compared to the first compound due to the additional carbon.
- **Conclusion**: CH2=CHCl is more resonance stabilized than CH2=CHCH2Cl.

3. **Pair 3: [C6H5Br, C6H5CH2Br]**
- **C6H5Br (Bromobenzene)**: Similar to chlorobenzene, the bromine atom has a lone pair that can participate in resonance with the benzene ring, allowing for delocalization.
- **C6H5CH2Br (Benzyl bromide)**: The bromine atom here is attached to a carbon that does not allow for resonance with the benzene ring. Thus, it does not benefit from resonance stabilization.
- **Conclusion**: C6H5Br is more resonance stabilized than C6H5CH2Br.

4. **Pair 4: [CH3COOH, CH3COO-]**
- **CH3COOH (Acetic acid)**: This molecule has some resonance stabilization due to the ability to delocalize the lone pair on the oxygen atom, but it is not fully charged.
- **CH3COO- (Acetate ion)**: The acetate ion has a negative charge that can be delocalized over the two oxygen atoms. This results in more resonance structures and greater stability compared to acetic acid.
- **Conclusion**: CH3COO- is more resonance stabilized than CH3COOH.

### Final Answers:
- Pair 1: C6H5Cl
- Pair 2: CH2=CHCl
- Pair 3: C6H5Br
- Pair 4: CH3COO-