Sn1 and S/R rotation

[adrakdavra]

---

Members don't see this ad.

1. what does Sn1 has to do with S/R rotation?

2. when sound waves travel from air to water , what happen to freq? I am thinking nothing, but I am not sure?

3. Camera lens is covered with thin film, and reflection of light? is the thin film going to decrease the reflection of light. ??? and if so, how ?

 

[PostBaccHopeful]

1. what does Sn1 has to do with S/R rotation?

2. when sound waves travel from air to water , what happen to freq? I am thinking nothing, but I am not sure?

3. Camera lens is covered with thin film, and reflection of light? is the thin film going to decrease the reflection of light. ??? and if so, how ?

I will attempt to answer your question #1. I've never heard of S/R rotation, but if you mean S/R configuration I would be able to answer this question. When undergoing a reaction (ie Sn1), your new product might have a new chiral carbon; hence, it will either be an S or R configuration. Please note that the direction of rotation due to a plane of polarized light (levorotatory/dextrorotatory aka L/D rotation) DO NOT have any influence on S/R configuration. This means that an S configuration can rotate a plane of polarized to the left or to the right and vice versa for R configuration.

I hope I answered your question, but I've never seen S/R rotation (unless that means S/R configuration).

 

[HotHamH2O]

1. what does Sn1 has to do with S/R rotation?

2. when sound waves travel from air to water , what happen to freq? I am thinking nothing, but I am not sure?

3. Camera lens is covered with thin film, and reflection of light? is the thin film going to decrease the reflection of light. ??? and if so, how ?

#1. I think you mean D/L rotation. SN1 reactions create racemic mixtures so you would have no optical rotation because you would have 50% of D and 50% of L. You would have to add more of either D or L to increase the concentration of one of the species to determine what the degree of rotation was. Then, since it's racemic you know the other one is just the opposite of the degree of the species you made more concentrated. The R/S on corresponds to the chiral carbon of the enantiomer.

#2. V = sqrt(E/d) where E is the elasticity of the medium and d is the density. Many people make the mistake of simply saying sound travels faster in denser mediums but that is not true if E is the same for the two mediums. Whats make sound travel faster, based on the equation, is the elasticity of the medium. For MCAT all you need to know is that for speed of sound solid > liquid > gas.

#3. It depends on how much the film defracts the light. I imagine if they are asking this, the film does not create a mirror like smooth surface. For example if the film is the oil from your fingers, then it will decrease the amount of light reflected because it will absorb some of the light and it will defract it in many different directions. This question requires more information for me to help you any further.