A sample of a substance containing only C and H burns in excess O2 to yield 4.4g of CO2 And 2.7 g of H2O. The empirical formula of a substance is?(C = 12, O...
A sample of a substance containing only C and H burns in excess O2 to yield 4.4g of CO2
And 2.7 g of H2O. The empirical formula of a substance is?(C = 12, O = 16, H = 1)
Answer Details
To determine the empirical formula of the substance, we need to find the ratio of the number of atoms of each element in the compound.
First, we need to find the number of moles of each product formed. Using the molar masses of CO2 (44 g/mol) and H2O (18 g/mol), we can calculate:
moles of CO2 = 4.4 g / 44 g/mol = 0.1 mol CO2
moles of H2O = 2.7 g / 18 g/mol = 0.15 mol H2O
Next, we need to determine the number of moles of carbon and hydrogen that were present in the original sample. We can use the amount of CO2 and H2O produced to calculate this:
moles of C = moles of CO2 = 0.1 mol C
moles of H = moles of H2O x 2 = 0.3 mol H
Now we can find the simplest whole-number ratio of carbon to hydrogen in the compound. Dividing the number of moles of each element by the smallest number of moles gives:
C: 0.1 mol / 0.1 mol = 1
H: 0.3 mol / 0.1 mol = 3
So the empirical formula of the compound is CH3.
Therefore, the correct option is (a) CH3.