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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: dja01 on September 09, 2019, 10:21:26 PM

Title: Index of Refraction
Post by: dja01 on September 09, 2019, 10:21:26 PM

Does anyone know how the refractive index would change as a few drops of 2-propanol is added to water? To cyclohexane? I don't need a numerical value, just a yes or no answer for the lab report sheet.

Title: Re: Index of Refraction
Post by: mjc123 on September 10, 2019, 04:32:06 AM

The RI of cyclohexane is higher than that of water. That of 2-propanol is roughly in the middle. So what do you think?

Title: Re: Index of Refraction
Post by: dja01 on September 10, 2019, 02:29:43 PM

Quote from: mjc123 on September 10, 2019, 04:32:06 AM

The RI of cyclohexane is higher than that of water. That of 2-propanol is roughly in the middle. So what do you think?

If I'm being honest, I've never encountered refractive indexes before. I'll take a shot, if the RI of 2-propanol is higher than water, then there will be a change. If the RI of cyclohexane is higher than 2 propanol, there will not be a change. Is this right?

Title: Re: Index of Refraction
Post by: mjc123 on September 11, 2019, 04:33:18 AM

No. To a first approximation, RI follows the rule of mixtures.

Why are you doing this question if you've never encountered refractive indexes before?

Title: Re: Index of Refraction
Post by: dja01 on September 13, 2019, 02:07:41 PM

It was the last question in our lab report. Seems like an added challenge question since we haven't really learned about it, so thats why I came here. Your initial response didn't really help my understanding, and the second response came too late, since I had unfortunately already had to turn in the report. Thanks anyway.