b c d please. thx!

b. S-ibuprofen has a specific rotation, [a]o = +54. What is the optical rotation of an ibuprofen solution that has 90% S and 10% R? c. 1 mol of a racemic ibuprofen is dissolved in methanol. Then 1 equivalent of the chiral amine (S)-1 amino-2-propanol is added. An acid-base reaction occurs (think what is the base and what is the acid!) Draw the two products (each an ammonium salt) that forms in the boxes provided HC. OH 2 ammonium salt products CHE NH2 CH2OH OH Hc1 CH, ibuprofen racemic (S)-1-Amino-2-propanol d. One of the ammonium salts crashes out of the methanol solution. Briefly explain why one product can be soluble and the other insoluble