nitroglycerin (used medically as a vasodilator to treat heart conditions): {\rm C} 15.87\% {\rm H} 2.22\% {\rm N} 18.50\% {\rm O} 63.41\%.
None of this makes sense to me.
Will you please explain the meaning of {\rm C} etc?
To determine the empirical formula of nitroglycerin (C15.87H2.22N18.50O63.41), we need to convert the percentages into moles.
Step 1: Convert percentages to grams.
The given percentages represent the mass percentages of carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) in nitroglycerin. Let's assume we have a 100g sample, which means:
Carbon (C): 15.87% of 100g = 15.87g
Hydrogen (H): 2.22% of 100g = 2.22g
Nitrogen (N): 18.50% of 100g = 18.50g
Oxygen (O): 63.41% of 100g = 63.41g
Step 2: Convert grams to moles.
To convert grams to moles, we need to divide the given mass by the molar mass of each element.
The molar mass of carbon (C) is 12.01 g/mol.
The molar mass of hydrogen (H) is 1.01 g/mol.
The molar mass of nitrogen (N) is 14.01 g/mol.
The molar mass of oxygen (O) is 16.00 g/mol.
Using these molar masses, we can calculate the number of moles for each element:
Number of moles of C: 15.87g / 12.01 g/mol = 1.32 mol
Number of moles of H: 2.22g / 1.01 g/mol = 2.20 mol
Number of moles of N: 18.50g / 14.01 g/mol = 1.32 mol
Number of moles of O: 63.41g / 16.00 g/mol = 3.96 mol
Step 3: Find the simplest ratio of moles.
The simplest ratio of moles can be obtained by dividing each number of moles by the smallest number of moles, which in this case is 1.32 mol:
C: 1.32 mol / 1.32 mol = 1 mol
H: 2.20 mol / 1.32 mol ≈ 1.67 mol
N: 1.32 mol / 1.32 mol = 1 mol
O: 3.96 mol / 1.32 mol ≈ 3 mol
The empirical formula of nitroglycerin is therefore C1H1.67N1O3 (simplified to CNO3H1.67).
If the previous two people were to use common sense, they might realize that Nitroglycerin is made up of carbon, hydrogen, nitrogen, and oxygen. If you look in the {}, you will see the chemical symbol for Carbon (C), Hydrogen (H), Nitrogen (N), and Oxygen (O). And if you had any experience with any sort of college (maybe even high school) chemistry, you would know that it is asking for you to calculate the empirical formula using the percents of the elements.
That should be obvious because any teacher would ask a question like this in chemistry.
This particular question is a 'copy' and 'paste' from a question from the Mastering Chemistry Website problems. (i know this because that is how i found this site)
Now that I have given you all of the necessary information, one of you should be able to answer it (or someone new, since this was posted 2.5 years ago)