Problem # 3: what is the molar mass of 35.0 g of an unknown substance that...
The molar mass of unknown molecular compound is determined using freezing point depression. The substance is dissolved in benzene (C6H), an organic solvent. Use the data below to determine the molar mass of the substance. 8.65 g Mass of unknown compound Freezing point of solution Volume of benzene -10.21°C 35.0 mL 5.53°C Freezing point of benzene Density of benzene Kf for benzene 0.8765 g/mL 5.12°C/m Molar mass = g/mol
2. A solution of an unknown molecular substance is prepared by dissolving 0.50 g of the unknown in 8.0 g of benzene. The solution freezes at 3.9°C. Determine the molar mass of the unknown. (Benzene has a freezing point of 5.5°C and a Kfvalue of 5.12°C/m) 10
A student is determining the molar mass of an unknown compound based on the following data: mass compound: 4.80 g mass solvent (water): 0.022 kg new freezing point: -2.50 oC freezing point depression constant (Kf): 1.86 oC/molal (Freezing point of pure water = 0 oC) 0.0786 g/mol 162.33 g/mol 0.00616 g/mol 293.26 g/mol
1.A solution that contains 15.581 grams of benzene (molar mass = 78.1 g/mol) in 420 g of cyclohexane freezes at a temperature 9.50 ºC below the freezing point of pure cyclohexane. Calculate the molar freezing point depression constant, Kf, for cyclohexane. 2. The molar boiling point elevation constant for water is 0.512 ºC/m. What is the boiling point of a solution containing 673 g of water and 78.0 g of CaCl2? 3. A solution containing 32.0 g of an unknown...
Colligative properties, need to calculate the molar mass of the unknown substance: Can you please show the work for this problem? Thanks! 13 A solution was prepared by dissolving 59.82 g of an unknown (non-ionic) substance to 100.0 g of water. The boiling point of this solution was measured to be 101.7°C. unknown substance. Determine the molar mass of the 13 A solution was prepared by dissolving 59.82 g of an unknown (non-ionic) substance to 100.0 g of water. The...
Freezing Point Depression: Determination of the Molar Mass of an Unknown Substance Laboratory Record Unknown Identifier #4 (All unknowns are nonelectrolytes, soi-1) Determination of the freezing point of pure l-butyl alcohol: (Record time-temperature data on the next page) 29.62 1. Mass of empty test tube 2. Mass of test tube and t-butyl alcohol after determination of freezing point of pure t-butyl alcohol 50.25 20.71 3. Mass of t-butyl alcohol Determination of the molar mass of an unknown: (Record time-temperature data...
What is the molar mass of a substance that when added to 1.000 kg of water lowers the freezing temperature by 1.2 ºC? The amount added to water was 38.20 g and the substance has a van't Hoff factor of 3.
Molar Mass Determination by Freezing Point Depression Calculate and enter the freezing point depression of a solution of 65.1 g ethylene glycol (C2H602) in 792 g H20. Kffor H2O is 1.86 °C kg/mol. °C 1homework pts Submit Answer Tries 0/5 A solution which contains 60.9 g of an unknown molecular compound in 325 g of water freezes at -3.24°C. What is the molar mass of the unknown? g/mol 1homework pts Submit Answer Tries 0/5
Pure benzene, C6H6, has a molar mass of 78.114 g mol-1, a density of 0.8765 g mL-1, a freezing point of 5.45°C, and a boiling point of 80.2°C. Its freezing point depression and boiling point elevation constants are: Kf = 5.07°C m-1; Kb = 2.53oC m-1. A solution was made by taking 33.88 g of an unknown nonelectrolyte and dissolving it in 175.0 g of benzene. The measured freezing point of the solution was 1.65oC. Calculate the molar mass of...
A solution containing 1.00 g of an unknown non-electrolyte liquid and 9.00 g water has a freezing point of -3.33 oC. The Kf = 1.86 oC/m for water. Calculate the molar mass of the unknown liquid, in g/mol.