Styrene (1.53 g, 0.011 mol) in methanol (30 mL) was added to a mixture of Hg(OAc)2 (5.30 g, 0.016 mol) in methanol (100 mL) at room temp. and stirred for 24 h. Sodium hydroxide (3.0 M, 16 mL) was added, followed by NaBH4 (0.32 g, 0.008 mol) in NaOH (3.0 M, 16 mL) at 0 °C. The precipitated Hg was removed by filtration. The product was isolated by diethyl ether extraction. After drying over Na2SO4, solvent was removed and distillation gave the product. (Adapted from: Senda, Y.; Kanto, H.; Itoh, H. J. Chem. Soc., Perkin Trans. 2 1997, 1143-1146.)

Styrene reacts in oxymercuration and demercuration in the present of methanol to form 1-methoxyethyl benzene.

Explanation:

See the attached file for the mechanism of reaction

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%