Question

You are given the percent by mass of the elements in a compound and wish to determine the empirical formula. Label each of the following statements as true or false and explain your answers.

a. You must assume exactly 100.0 g of the
compound.
b. You must convert percent by mass to relative
numbers of atoms.
c. You must divide all of the percent by mass
numbers by the smallest percent by mass.
d. You cannot solve for the emp

Answer 1

a) False, you can use any basis, 1 g, 100 g, 100 kg, or any other value. The relative proportions will remain the same.
b) True, since an empirical formula is defined by the number of atoms of each element, it is this number of atoms, rather than atomic mass, that is needed.
c) False, you would have to divide the numbers of atoms by the smallest number of atoms. (not the mass %s)
d) False, it is possible given the % by mass.