Question

please help ?

MST SHOW ALL CALCULATIONSs. Please be neat. Use correct significant figures. 1. A student masses an empty flask, aluminum foil (witha small pinhole), and copper wire and finds the mass to be 54.8680 g. She then adds about 5.0 mL of an unknown liquid and heats the flask in a hot waterbath to 95.0 °C. After all the liquid is vaporized, she removes the flask from the bath and masses it after it has cooled. The mass of the flask, foil, wire, and unknown liquid was found to be 55.8020 g. The volume of the flask is 242.5mL and barometric pressure was 747.0 mm Hg (Torr) Show calculations for all conversions and use the correct number of sig figs. a. What was the pressure of the vapor in the flask in atmospheres? P= atm. b. What was the temperature of the vapor in Kelvin? The volume of the flask in Liters? V= T= к c. What was the mass of the vapor that was present in the flask? grams gas= d. What is the mass of one mole of vapor? (equation # 2 ) watch sig figs g/mol MM= 2. This question asks you to consider how certain procedural errors would change the molar mass calculated in this experiment. Give your reasoning in each case. Please use complete words and sentences (including proper spelling). CIRCLE YOUR CHOICE a. If all of the unknown liquid has not fully vaporized, would the result for the molar mass be higher or lower (circle one) as compared to a properly done experiment? Explain your answer. 7

Answer 1

Pressure of vapor (P) : Temperaine ofVapor (T)= (95273) K Volume of the Plask (v) 747 760 O.983 au CAns) 368 K CAns) (242 O. 2425 L CAns) IOOO Mass Vabor 65.8020-54 8680) O.934 (Ans) 2 d) Now, PV= nRT RT O.934x0.0821x368 O.983 x 0 2425 WRT 113.38md CANS) PV