Acetaminophen (c8h9no2) is the active ingredient in many nonprescription pain relievers. each tablet contains 500 mg of acetaminophen, and a typical adult dose is two tablets every eight hours.
• determine the molar mass of acetaminophen (show your work).
• calculate the number of moles of acetaminophen in a single tablet (show your work).
• calculate the number of moles of acetaminophen that an adult would have taken if she took three doses of acetaminophen in one day (show your work).

1) Molar mass C8H9NO2

Element    Atomic mass    # of atoms   mass
                       g/mol                                  g
C               12                         8               12*8 = 96
H                 1                         9                1*9 =    9
N               14                         1               14*1 = 14
O               16                        2                16*2 = 32

                              molar mass =   96 + 9 + 14 + 32 = 151 g/mol

2) Number of mols in a tablet

# of moles = mass / molar mass = 0.500 g / 151 g/mol = 0.003311 moles

3) 3 doses * 2 tablets * 0.003311 moles / tablet = 0.020 moles

They are like other investigations? say there was a murder u have to do blood test and finger prints which run through a lab. 

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant.