Answer Happy

2. (5 points) The density of an unknown compound is 1.143 g/ml. How many X atoms are present in a 1.93 x 10'nL sample of B ZX ? Assume the molar mass is 256.32 g/mol 3.19 points) Give the balanced molecular, total ionic and net ionic equation for the reaction of acetic acid and rubidium nitrate. For full points, include all charges and all states of matter. 4. (5 points) The titration of 61.5 ml of an unknown concentration of phosphoric acid solution requires 150.3 mL of a 0.1562 M magnesium hydroxide solution to reach the equivalence point. What is the concentration of the phosphoric acid (M)? 5. (10 points) 106 ml of a 3.42 M hydroiodic acid solution is reacted with 55.6 g of magnesium metal. Hydrogen gas is produced and was collected by water displacement at 737. torr and a temperature of 34.2°C. What is the volume of the collected gas under these conditions? Water vapor pressure at 34.2°C - 39.8 torr. 6. (15 points) a. Draw the heating curve for the following for an unknown compound. Label each phase of the diagram with the appropriate state(s) of matter. b. How much energy is removed from a 6.8 g of an unknown sample at 415K to solidify the sample and lower the temperature to 225K. The boiling point of the unknown compound 360K. The melting point is 265K. Assume the molar mass of the unknown compound is 132.4 g/mol. The following values are the specific heat capacities of each phase and the change in enthalpy for each phase change: Gaseous C: 1.353/g°C Liquid Cy: 1.56J/g°C Solid Cy: 1.25J/g°C AHvap = 29.45 kJ/mol AHtus - 9.55 kJ/mol 7. (5 points) Carbon tetrachloride has a normal boiling point of 67.9°C and a heat of vaporization of 42.7 kJ/mol. What is the vapor pressure of carbon tetrachloride at 12.0°C? 8. a. (3 points) List the dominant intermolecular force for each of the following substances.

4. (5 points) The titration of 61.5 mL of an unknown concentration of phosphoric acid solution requires 150.3 mL of a 0.1562 M magnesium hydroxide solution to reach the equivalence point. What is the concentration of the phosphoric acid (M)? 5. (10 points) 106 mL of a 3.42 M hydroiodic acid solution is reacted with 55.6 g of magnesium metal. Hydrogen gas is produced and was collected by water displacement at 737. torr and a temperature of 34.2°C. What is the volume of the collected gas under these conditions? Water vapor pressure at 34.2°C - 39.8 torr.. 6. (15 points) a. Draw the heating curve for the following for an unknown compound. Label each phase of the diagram with the appropriate state (s) of matter. b. How much energy is removed from a 6.8 g of an unknown sample at 415K to solidify the sample and lower the temperature to 225K. The boiling point of the unknown compound 360K. The melting point is 265K. Assume the molar mass of the unknown compound is 132.4 g/mol. The following values are the specific heat capacities of each phase and the change in enthalpy for each phase change: Gaseous C: 1.35 J/g°C Liquid C: 1.56 J/g°C Solid C: 1.25 J/g°C AHvap 29.45 kJ/mol - AHfus 9.55 kJ/mol