Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Chapter 5
Organic Chemistry- Exam 2
| Question | Answer |
|---|---|
| What are isomers? | Different compounds that have the same molecular formula. |
| What are stereoisomers? | Compounds with the same connectivity but different 3-D arrangements |
| When can cis/trans notation be used for alkenes? | When there is a like group on each alkene carbon. |
| Why can't C=C bonds freely rotate? | Maintaining π-bond orbital overlap prevents free rotation. |
| What is a chiral object? | An object that is not identical to its mirror image. |
| What does superimposable mean? | Two objects can be placed over one another so all parts coincide. |
| What commonly creates chirality at carbon? | A carbon bonded to four unique groups. |
| What is a chirality center? | A tetrahedral atom attached to four different groups. |
| What are enantiomers? | Stereoisomers that are non-superimposable mirror images |
| Can an achiral compound have an enantiomer? | No. |
| How can an enantiomer often be drawn from a chiral structure? | Invert the dashes and wedges at the chirality center(s). |
| What do enantiomers have at corresponding chirality centers? | Opposite configurations. |
| What system assigns R or S configuration? | The Cahn–Ingold–Prelog (CIP) system. |
| How is CIP priority assigned? | Higher atomic number gets higher priority. |
| What should you do with the lowest-priority group when assigning R/S? | Orient it away from you. |
| What does clockwise 1→2→3 indicate? | R configuration. |
| What does counterclockwise 1→2→3 indicate? | S configuration. |
| How are tied priorities resolved in CIP? | Compare atoms one layer at a time until the first point of difference. |
| How are double bonds treated for CIP comparison? | As if the bonded atom is attached to two equivalent atoms. |
| What happens if two groups on a chirality center are switched? | The configuration becomes the opposite configuration. |
| What do R and S describe? | The configuration at a chirality center. |
| What do (+) and (−) describe? | The direction of optical rotation. |
| Is there a direct correlation between R/S and (+)/(−)? | No |
| What does optically active mean? | Able to rotate plane-polarized light. |
| What is a racemic mixture? | A 50/50 mixture of two enantiomers. |
| What is the optical rotation of a racemic mixture? | 0°, because the rotations cancel. |
| What are diastereomers? | Stereoisomers that are not mirror images. |
| How do diastereomers differ from enantiomers in physical properties? | Diastereomers have different physical properties. |
| What is the maximum number of stereoisomers for n chirality centers? | 2^n, before accounting for symmetry/meso compounds. |
| Can a molecule with multiple chirality centers be achiral? | Yes, if it has an appropriate plane of symmetry. |
| What is a meso compound? | A compound with chirality centers that is achiral because of symmetry. |
| What does a plane of symmetry imply? | The molecule is achiral. |
| What do horizontal lines represent in a Fischer projection? | Attachments coming out of the page. |
| What do vertical lines represent in a Fischer projection? | Attachments going back into the page. |
| How may a Fischer projection be rotated without changing the molecule? | Only 180° in the plane; do not flip it. |
| When is E/Z notation used for alkenes? | When the alkene substituents make cis/trans inadequate. |
| How are E/Z priorities assigned? | Prioritize the groups attached to each alkene carbon by atomic number. |
| When is an alkene Z? | The highest-priority groups are on the same side. |
| When is an alkene E? | The highest-priority groups are on opposite sides |
Created by:
KristenR2025