What is the total sample size (in grams)for a sample of ethanol (CH3CH2OH) which contains 3.39 grams of oxygen?
Use proportion:
sample mass
=3.39*(RMM of C2H5OH)/(RAM of O=16)
=? g
To determine the total sample size of ethanol (CH3CH2OH) based on the amount of oxygen present, we need to use the molar ratios and molar masses of the elements in ethanol.
The first step is to find the molar mass of oxygen (O). The molar mass of oxygen is 16 grams per mole (g/mol).
Next, we need to find the molar mass of ethanol (C2H5OH). To do this, we'll multiply the molar mass of each element by the number of atoms of that element in one molecule of ethanol and sum them up.
C: (12.01 g/mol) x 2 = 24.02 g/mol
H: (1.01 g/mol) x 6 = 6.06 g/mol
O: (16.00 g/mol) x 1 = 16.00 g/mol
Adding these masses together gives the molar mass of ethanol:
24.02 g/mol + 6.06 g/mol + 16.00 g/mol = 46.08 g/mol
Now we have all the information needed to find the total sample size of ethanol. We'll use the molar ratio between oxygen and ethanol to set up a proportion.
Molar ratio: 1 mol O / (1 mol ethanol) = 16 g O / (46.08 g ethanol)
We'll solve for the total sample size (in grams) of ethanol using the given mass of oxygen:
(x g ethanol / 3.39 g O) = (46.08 g ethanol / 16 g O)
Cross-multiplying:
16 g O * x g ethanol = 3.39 g O * 46.08 g ethanol
Dividing both sides by 16 g O:
x g ethanol = (3.39 g O * 46.08 g ethanol) / 16 g O
Calculating this gives us:
x g ethanol = 9.68 g ethanol
Therefore, the total sample size of ethanol is 9.68 grams when it contains 3.39 grams of oxygen.