Here is a post lab question that I need answered from my "Determination of Molar Mass by Freezing Point" post-lab.
Question:
**NOTE**
DOUBLE CHECK YOUR FINAL ANSWER AND MAKE SURE YOU SHOW ALL WORK, I WILL DOWNRATE IF THE QUESTION IS INCORRECT SO PLEASE MAKE SURE EVERYTHING LOOKS GOOD. ONLY HIGH RATING TO CORRECT ANSWERS THANKS!
ALSO ANSWER ALL SUBPARTS NOT JUST ONE THANKS!
7. A forensic chemist is given a white solid that is suspected of being pure cocaine (C17H21NO4, molar mass 303.35 g/mol). She dissolves 1.22 t 0.01 g of the solid in 15.60 t 0.01 gbenzene. The freezing point is lowered by 1.32 t 0.04 oC. a. What is the molar mass of the substance? b. Assuming that the percent uncertainty in the calculated molar mass is the percent uncer- tainty in the temperature change, calculate the uncertainty in the molar mass. c. Could the chemist unequivocally state that the substance is cocaine? For example, is the uncertainty small enough to distinguish cocaine from codeine (C18H21NO3, molar mass 299.36 g/mol)? d. Assuming that the absolute uncertainties in the measurements of temperature and mass remain unchanged, how could the chemist improve the precision of her results?
