[Bidagdha_TADIR]

Suppose, there are two different compounds 'X' and 'Y'. They are not enantiomers. 'X' has a specific rotation of +12° and 'Y' has a specific rotation of -12°. Now,

1. Will there be any net optical rotation of a solution that contains equal conc. of 'X' and 'Y'?

2. Will there be any net optical rotation of a solution that contains equal amount of 'X' and 'Y'?

[sjb]

Suppose, there are two different compounds 'X' and 'Y'. They are not enantiomers. 'X' has a specific rotation of +12° and 'Y' has a specific rotation of -12°. Now,

1. Will there be any net optical rotation of a solution that contains equal conc. of 'X' and 'Y'?

2. Will there be any net optical rotation of a solution that contains equal amount of 'X' and 'Y'?

What are your thoughts? For instance, consider the definition of specific rotation.

[Arkcon]

Please give us a definition of what you mean by the two words, concentration and amount.  Given the nature of the analysis, doers the fact that they aren't enatiomers matter?  Or is that part of what we mean -- concentration vs amount.

[Bidagdha_TADIR]

@ Arkcon. Okay. Lets say in the first instance 'X' is present at 0.2M conc. and 'Y' is also present at 0.2M conc. In the second instance, say that 500mg of 'X' and 500mg of 'Y' was dissolved and 1L of solution was produced; then the optical rotation of the solution was measured.

@sjb. I think that there will be a net optical rotation in the second instance because while the specific optical rotation is conc.-independent, optical rotation IS conc.-dependent; and same amount doesn't translate into same conc. I am not sure what will happen in the first instance though.