1) What mass of NaCl is dissolved in 250 g of water in a0.050m solution. 2) calc
ID: 676815 • Letter: 1
Question
1) What mass of NaCl is dissolved in 250 g of water in a0.050m solution. 2) calculate the freezing points of aqueous solutions of 0.10m glucose and 0.10 m barium chloride (BaCl2) 3) calculate the molality of commercial available HCl from thefollowing data formula weight 36.465, density of the solution(g/ml) 1.19, weight % 37.2 and Molarity 12.1 4) A solution of 2.0 g of an unknown substance in 50.0g ofcyclohexane ( freezing point = 6.6 degrees celsius and Kf = 20.4degree celsius/m) freezes at 1.05 degrees celsius. what is themolar mass of the unknown substance. 1) What mass of NaCl is dissolved in 250 g of water in a0.050m solution. 2) calculate the freezing points of aqueous solutions of 0.10m glucose and 0.10 m barium chloride (BaCl2) 3) calculate the molality of commercial available HCl from thefollowing data formula weight 36.465, density of the solution(g/ml) 1.19, weight % 37.2 and Molarity 12.1 4) A solution of 2.0 g of an unknown substance in 50.0g ofcyclohexane ( freezing point = 6.6 degrees celsius and Kf = 20.4degree celsius/m) freezes at 1.05 degrees celsius. what is themolar mass of the unknown substance.Explanation / Answer
1) Molality = 0.050 mols of NaCl / 1 kg of water 250 g water = 0.250 kg water Use your known molality to find out how many moles of NaCl youhave. (0.050 mols NaCl / 1 kg of water)*(0.250 kg water) = 0.0125mols NaCl Use your moles of NaCl and the molar mass of NaCl to find themass of NaCl. 0.0125 mols NaCl * (58.443 g NaCl / 1 mol NaCl) = 0.731 gNaCl 2) For glucose.... Tf =iKfm i = 1(for covalent compounds) Kf = 1.86 degrees/m (thats for water as a solvent, which we have) Tf = (1)(1.86 deg/m)(0.10 m) =0.186 degrees Tsolution = Tsolvent -Tf = 273.15 K - 0.186 K = 273. K Do the same thing for barium chloride...just remember that youhave an ionic compound so "i" will not be 1. = 273.15 K - 0.186 K = 273. K Do the same thing for barium chloride...just remember that youhave an ionic compound so "i" will not be 1.Related Questions
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