A 0.160 M solution of an enantiomerically pure chiral compound D has an observed rotation of 0.20° in a 1-dm sample container. The molar mass of the compound is 128.0 g/mol.

(a) What is the specific rotation of D?

(b) What is the observed rotation if this solution is mixed with an equal volume of a solution that is 0.160 M in L, the enantiomer of D?

(c) What is the observed rotation if the solution of D is diluted with an equal volume of solvent?

(d) What is the specific rotation of D after the dilution described in part (c)?

(e) What is the specific rotation of L, the enantiomer of D, after the dilution described in part (c)?

(f) What is the observed rotation of 100 mL of a solution that contains 0.01 mole of D and 0.005 mole of L? (Assume a 1-dm path length.)

I feel like I've been running around in circles with this problem. I keep plugging in the numbers for the rotation formula but I keep getting this wrong. I would rather not have the answers to these problems, but if someone could tell me which equations and formulas I should be plugging in for each problem so I can find the answers on my own, that would be great. Thanks!

Well, let's see if I can help you find your way out of this circle. Don't worry, I won't clown around too much with the formulas.

(a) The specific rotation is given by the equation:
specific rotation = observed rotation / (concentration * path length)
In this case, the concentration is 0.160 M and the path length is 1 dm. So you just need to plug those values in to find the specific rotation of D.

(b) When you mix equal volumes of D and L solutions, their concentrations will add up. So the total concentration in the mixture will be 0.160 M + 0.160 M = 0.320 M. Now you can use the same specific rotation formula as in part (a), but with the new concentration.

(c) When you dilute the solution of D with an equal volume of solvent, the concentration will be halved. So you will have 0.080 M of D. Again, use the specific rotation formula to find the new observed rotation.

(d) The specific rotation of D remains the same after dilution because it is an intrinsic property of the compound. So the specific rotation of D after the dilution is the same as in part (a).

(e) The specific rotation of L is the negative of the specific rotation of D, since it's the enantiomer. So just take the negative value of the specific rotation of D after the dilution.

(f) To find the observed rotation of 100 mL of the solution containing D and L, you need to calculate the concentrations of D and L in the solution. To do that, use the provided number of moles and the volume of the solution. Then use the specific rotation formula to find the observed rotation.

I hope this helps you find your way through these calculations! Good luck, and try not to get dizzy from going in circles!

No problem! Let's break down each part of the problem and identify the equations and formulas you can use to solve them:

(a) To find the specific rotation of D, you can use the equation:
specific rotation = observed rotation / (concentration (in g/mL) x path length (in dm))
Here, you are given the observed rotation (0.20°) and the concentration (0.160 M) of the solution. The molar mass given (128.0 g/mol) is used to convert concentration from M to g/mL.

(b) When you mix an equal volume of the enantiomer L with the solution of D, the resulting observed rotation is given by:
observed rotation = (observed rotation of D x concentration of D) + (observed rotation of L x concentration of L)
You are given the concentration of the solution of D (0.160 M) and the concentration of the solution of L (also 0.160 M).

(c) If the solution of D is diluted with an equal volume of solvent, the new concentration of D is halved, so the observed rotation can be calculated using the same equation as part (b), with the diluted concentration of D.

(d) The specific rotation of D after the dilution described in part (c) can be calculated by using the diluted concentration of D in the equation from part (a).

(e) The specific rotation of L after the dilution described in part (c) can also be calculated using the same equation as part (d), but using the concentration of L after dilution.

(f) To find the observed rotation of 100 mL of the D and L mixture, you can use the equation from part (b), but first convert the moles to concentrations by dividing the moles by the total volume of the mixture (in L).

Remember to pay attention to units and convert as needed. Now that you know which equations and formulas to use for each part, you can apply them to find the answers. Good luck!

I can help you with that! Let's break down each part of the problem and identify the equations and formulas you can use to solve them.

(a) To find the specific rotation of D, you can use the formula:

Specific Rotation (α) = observed rotation (α_obs) / (concentration (c) x path length (l))

In this case, the observed rotation (α_obs) is given as 0.20°, the concentration (c) is 0.160 M, and the path length (l) is 1 dm. You also know the molar mass of D, which is 128.0 g/mol. Use these values to calculate the specific rotation.

(b) When you mix the solution of D with the enantiomer L in equal volumes, the concentration of D and L in the resulting solution will be halved (0.080 M). To find the observed rotation, you can use the same formula as in part (a), but with the new concentration.

(c) When you dilute the solution of D with an equal volume of solvent, the concentration of D will be halved (0.080 M) and the path length will be doubled (2 dm). Use the same formula as in part (a), but with the new concentration and path length.

(d) To find the specific rotation of D after the dilution described in part (c), use the formula from part (a) with the new concentration and path length.

(e) The specific rotation of L, the enantiomer of D, does not change. It will still have the same specific rotation as D before the dilution.

(f) To find the observed rotation of a 100 mL solution containing 0.01 mole of D and 0.005 mole of L, you need to first calculate the concentrations of D and L. The concentration of D is 0.01 mole / 0.1 L = 0.10 M, and the concentration of L is 0.005 mole / 0.1 L = 0.05 M. Once you have the concentrations, you can use the same formula as in part (a) to find the observed rotation.

Remember to use consistent units for the calculations (e.g., convert degrees to radians if necessary). I hope this helps!

Well im a bit late... 6 yrs late but ill be glad to answer this question

A. I spent 7hr on this question so here is the answer
If the wave is 7.13 then the value of decrepit is 9.21 if the value is equal to 99. then the value is money * sin of COVid YES THIS IS 2020