Question

1. In a recent study by Cornell University. Grade A dark maple syrup was found to be 66.2 % sucrose (C12Hz2011) by mass. Maple syrup has a density of 1.37 g/mL. Assume this is the sucrose content of maple sugar for all questions that follow. a. Calculate the molality, mole fraction, and molarity of maple syrup. Assume water is the solvent b. Based on your answer to a, calculate the boiling point and the freezing point of maple syrup c. In reality maple syrup contains many solutes in addition to sucrose. Given this, if you were to take the boiling point of maple syrup would that boiling point be higher than, less than or equal to the boiling point you calculated in 1b? Explain your answer.

Answer 1

18 Answeris: af Molecular weight of sucrose = 342 gr. 66.2% sucrose solution meam . (100 - 66.2) = 33.8 gm water contains 66.2 gm sucrose 100 gm u 195.86 gm So, molality - 195.36 x 1000 x 342 = 5.727 (m) mole fraction of sucrose in the solution 66.2 342 66.2 & 33.8 342 -0.0934 mole fraction of water =1-0.0934 = 0.906 The density of maple syrup = 1.37 gime +37 gor solutions in sucrose syrup I ml maple contain 1.37 .: Molarity 1.37x1000 = = 4 M 342 b Eleration of boiling poin STO = kox m kg = molal ebullioscopic constant 10 = 0.51345.727 = 0.513 king mat) -2.935°C syroup = (100+ 2.938)°C Soy boiling point of maple poin 102.938 Depression of freezing point - AI = Brom <kg = cryoscopic contant -- 1.86 X 5-727 -1.36 kkg.mor - 10.65 °C So, freezing point of maple syrup = - 10.65°C es since maple syrup contains many solutes in addition to sucrose so X the actual rap our pressware at the calaulated boiling point is less and more eleration of tempr. tis required for its boiling. So the actual boiling point is Righer than calculated B.