Butanedione, a component of butter and body odor, has a cheesy smell. Elemental analysis of butanedione gave the mass percent composition: C, 55.80%; H, 7.03%; O, 37.17%. The molar mass of butanedione is 86.09 g/mol. Determine the molecular formula of butanedione.

The answer to your question is       C₄H₆O₂

Explanation:

Data

C = 55.80%

H = 7.03 %

O = 37.17 %

Molar mass = 86.09 g/mol

Molecular formula = ?

Process

1.- Express the percents as grams

C = 55.80g

H = 7.03g

O = 37.17g

2.- Convert the grams to moles

Carbon

                                  12 g of C 1 mol

                                  55.80 g   x

                                  x = (55.80 x 1)/12

                                  x = 4.65 moles

Hydrogen

                                  1 g of H  1 mol

                                  7.03 g      x

                                 x = 7.03 moles

Oxygen

                                  16 g of O 1 mol

                                   37.17 g    x

                                   x = 2.32 moles

3.- Divide by the lowest number of moles

Carbon          4.65/2.32 = 2

Hydrogen      7.03/2.32 = 3

Oxygen          2.32/2.32 = 1

4.- Write the empirical formula

                          C₂H₃O

5.- Calculate the molar mass of the empirical formula

    C₂H₃O  = (12 x 2) + (3 x 1) + (16 x 1) = 24 + 3 + 16 = 43 g

6.- Divide the molar mass of butanedione by the molar mass of the empirical formula

                           86.09/43 = 2

7.- Multiply the empirical formula by two

                          C₄H₆O₂

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !