It was found that compound contained 68.1% carbon, 13.7% hydrogen, and 18.2% oxygen by mass.
a. find empirical formula for the compound.
b. if the molar mass of the compounds is 176.34 g/mol, what it’s the molecular formula?

A. The empirical formula is the simplest ratio of components making up a compound.

In 100 g of the compound

                             C                            H                               O

mass               68.1 g                         13.7 g                         18.2 g

number of moles

                    68.1 g / 12 g/mol        13.7 g / 1 g/mol         18.2 g / 16 g/mol

                     = 5.68 mol                 = 13.7 mol                 1.14 mol

divide by the least number of moles - which is 1.14 mol

                  5.68 / 1.14 = 5.0             13.7 / 1.14 = 12.0     1.14 / 1.14 = 1.0

the ratio of the components C : H : O is 5: 12 : 1

therefore empirical formula is C₅H₁₂O

B. Molecular formula is the actual ratio of the components making up the compound. We need to find the mass of the empirical formula / empirical unit and then find how many empirical units make up the molecular formula

mass of 1 empirical unit - C₅H₁₂O  - 12 g/mol x 5 + 1 g/mol x 12 + 16 g/mol x 1

                                       = 60 + 12 + 16 = 88 g

number of empirical units = molecular formula mass / mass of 1 empirical unit

                                           = 176.34 g/mol  / 88 g = 2.00 = 2

there are 2 empirical formulas in the molecular formula

therefore molecular formula  = 2 x (C₅H₁₂O) = C₁₀H₂₄O₂ ,

therefore molecular formula is C₁₀H₂₄O₂

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )

28528289 29823282 8298232 39858