Quiz: Orgo 2 ortho para and meta directors
This quiz set covers ortho, para, and meta directors in organic chemistry, focusing on their effects on electrophilic aromatic substitution reactions.
Quiz(32 questions)
1. Which of the following groups is considered an ortho/para director?
Terms in this Study Set(32)
Ortho and Para Directors(18)
What are ortho and para directors?
Ortho and para directors are substituents that direct electrophilic aromatic substitution to the ortho and para positions of an aromatic ring.
Name a common ortho/para director.
Examples include -OH (hydroxyl), -OCH₃ (methoxy), and -NH₂ (amino) groups.
True or False: Halogens are ortho/para directors.
True. Halogens (like -Cl, -Br) are ortho/para directors due to their ability to donate electrons through resonance.
Ortho and para directors: Electrophile or nucleophile?
Electrophile. They enhance the electron density of the aromatic ring, making it more reactive towards electrophiles.
Fill in the blank: The presence of ________ in a substituent makes it an ortho/para director.
lone pairs or double bonds.
Which position is favored in ortho/para directors?
Both ortho and para positions are favored, but steric hindrance can make one position more favorable.
How do resonance structures relate to ortho/para directors?
Ortho/para directors can stabilize the carbocation intermediate via resonance, enhancing reaction rates.
Compare ortho and para positions in substitution reactions.
Ortho positions can face steric hindrance, while para positions often yield higher substitution rates due to less crowding.
True or False: Alkyl groups are ortho/para directors.
True. Alkyl groups (like -CH₃) donate electrons and direct substitution to ortho and para positions.
Describe the effect of a -NO₂ group on substitution.
-NO₂ is a meta director, as it withdraws electrons, making ortho and para positions less favorable.
What is an example of a reaction involving an ortho director?
The nitration of anisole (methoxybenzene) leads to substitution at the ortho and para positions of the ring.
Name two ortho and para directing groups.
-OH (hydroxyl), -NH₂ (amino) - both increase electron density in the aromatic ring.
Cause → Effect: Why do ortho/para directors increase reactivity?
They stabilize the positive charge in the carbocation intermediate through resonance, making substitution more favorable.
Which substituent directs para over ortho?
Sterically bulky groups (like -tBu) favor para substitution due to reduced steric clashes.
What happens during electrophilic aromatic substitution with ortho/para directors?
The electrophile attacks the aromatic ring, preferentially at the ortho or para position, forming a sigma complex.
Fill in the blank: The ________ of the aromatic ring increases with ortho/para directors.
nucleophilicity.
True or False: -COOH is an ortho director.
False. -COOH is a meta director due to its electron-withdrawing effect.
What type of bond is formed during electrophilic aromatic substitution?
A sigma bond is formed when the electrophile attacks the carbon atom of the aromatic ring.
Meta Directors(14)
Identify a common meta director.
Nitro group (-NO2) is a meta director.
True or False: Meta directors stabilize carbocation intermediates.
False. Meta directors destabilize carbocation intermediates.
Fill in the blank: Meta directors are typically ___________.
electron-withdrawing groups.
How does a meta director affect substitution?
They direct electrophilic substitution to the meta position.
Compare ortho/para directors and meta directors.
Ortho/para directors donate electrons; meta directors withdraw electrons.
What is the effect of a halogen on substitution?
Halogens are weakly deactivating meta directors.
Example: What happens with nitrobenzene?
Electrophilic substitution occurs at the meta position, yielding meta-substituted products.
List two examples of meta directors.
- Carbonyl groups (-C=O) - Sulfonyl groups (-SO3H)
Cause → Effect: What happens with a strong electron-withdrawing group?
It directs substitution to the meta position.
True or False: Meta directors favor para substitution.
False. Meta directors do not favor para substitution.
What role does resonance play in meta directing?
Resonance structures stabilize ortho/para positions, not meta.
Identify the role of a carboxylic acid group.
It's a meta director due to its electron-withdrawing nature.
What is the main characteristic of meta directors?
They have electron-withdrawing effects that hinder nucleophilicity.
Meta directors in electrophilic aromatic substitution lead to __________.
substitution at the meta position.
Questions in this Study Set(32)
1. Which of the following groups is considered an ortho/para director?
2. Which of the following is a common example of a meta director?
3. True or False: The -NH₂ group is a meta director.
4. True or False: Meta directors stabilize carbocation intermediates.
5. Which of the following is NOT an ortho/para director?
6. Fill in the blank: Meta directors are typically ___________.
7. What is the primary reason ortho/para directors enhance the reactivity of an aromatic ring?
8. How do meta directors affect the position of substitution?
9. Which of the following statements about electrophilic aromatic substitution is true?
10. Compare the effect of ortho/para directors to meta directors.
11. What happens to the reaction rate when a bulky ortho/para director is present?
12. What is the effect of a halogen on electrophilic substitution?
13. Fill in the blank: The presence of ________ in a substituent typically makes it an ortho/para director.
14. When performing electrophilic substitution on nitrobenzene, what is the expected outcome?
15. True or False: Alkyl groups such as -CH₃ are meta directors.
16. Which of the following is NOT a known meta director?
17. Which position is generally favored for substitution when an ortho/para director is present?
18. Cause → Effect: What happens when a strong electron-withdrawing group is present?
19. Which of the following groups does NOT stabilize the carbocation intermediate during electrophilic substitution?
20. True or False: Meta directors favor substitution at the para position.
21. What type of bond is formed when an electrophile attacks the aromatic ring?
22. What role does resonance play in the behavior of meta directors?
23. How does resonance influence ortho/para directors?
24. Identify the role of a carboxylic acid group in electrophilic aromatic substitution.
25. Which of the following is a characteristic of ortho/para directing groups?
26. What is the main characteristic of meta directors in reactions?
27. Which position is typically less hindered during electrophilic aromatic substitution?
28. In electrophilic aromatic substitution, meta directors lead to __________.
29. Fill in the blank: The presence of a hydrocarbon chain like -C₃H₇ typically acts as a(n) ________ director.
30. Which of the following reactions serves as an example of an ortho/para directing group at work?
31. What is the effect of a -OCH₃ group on electrophilic aromatic substitution?
32. Which of the following statements is true regarding ortho/para directors?
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