The rotten smell of a decaying animal carcass is partially due to a nitrogen-containing compound called putrescine. Elemental analysis of putrescine indicates that it consists of: C, 54.50%, H, 13.73%, and N, 31.77%. Calculate the empirical formula of putrescine.
C, 54.50%, H, 13.73%, and N, 31.77%.
Take 100 g sample.
C = 54.50 g
H = 13.73 g
N = 31.77 g Now convert to mols.
mols C = C = 54.50 g/12.01 = 4.54
mols H = 13.73 g/1.008 = 13.62
mole N = 31.77 g/14.01 = 2.27
Find the ratio of these elements with whole numbers being no less than 1.The easy way to do that is to divide the smallest number by itself. Follow suit with the others.
mols C = 4.54/2.27= 2.00
mols H = 13.62/2.27 = 6.00
mole N = 2.27/2.27 = 1.00
So the formula is ............
CHECK MY WORK TO MAKE SURE I DIDN'T MAKE A TYPO WITH THOSE NUMBERS.
hjh
Putrescine, eh? Sounds like the life of the party! Let's crunch those numbers and figure out its empirical formula.
Step 1: Convert the percentages to masses:
Carbon (C): 54.50 g
Hydrogen (H): 13.73 g
Nitrogen (N): 31.77 g
Step 2: Convert the masses to moles:
Molar mass of carbon (C): 12.01 g/mol
Molar mass of hydrogen (H): 1.01 g/mol
Molar mass of nitrogen (N): 14.01 g/mol
Moles of carbon (C): 54.50 g / 12.01 g/mol ≈ 4.54 mol
Moles of hydrogen (H): 13.73 g / 1.01 g/mol ≈ 13.60 mol
Moles of nitrogen (N): 31.77 g / 14.01 g/mol ≈ 2.27 mol
Step 3: Divide each mole value by the smallest mole value:
Moles of carbon (C): 4.54 mol / 2.27 mol ≈ 2 mol
Moles of hydrogen (H): 13.60 mol / 2.27 mol ≈ 6 mol
Moles of nitrogen (N): 2.27 mol / 2.27 mol = 1 mol
Step 4: Simplify the ratio:
Empirical formula of putrescine: C2H6N
Voila! The empirical formula of putrescine is C2H6N. Now, enough chemistry - let's clear the air, shall we?
To calculate the empirical formula of putrescine, we need to determine the ratio of the atoms present in the compound.
1. Start by assuming that we have 100 grams of putrescine, which makes calculations easier.
2. Next, convert the percentages to grams. To do this, multiply the percentage by the assumed 100 grams:
- Carbon (C): 54.50% * 100 g = 54.50 g
- Hydrogen (H): 13.73% * 100 g = 13.73 g
- Nitrogen (N): 31.77% * 100 g = 31.77 g
3. Convert the grams to moles. To do this, divide the grams by the atomic mass of each element:
- Carbon (C): 54.50 g / 12.01 g/mol = 4.54 moles
- Hydrogen (H): 13.73 g / 1.01 g/mol = 13.60 moles
- Nitrogen (N): 31.77 g / 14.01 g/mol = 2.27 moles
4. Find the smallest whole number ratio by dividing all the mole values by the smallest mole value:
- Carbon (C): 4.54 moles / 2.27 moles = 2
- Hydrogen (H): 13.60 moles / 2.27 moles = 6
- Nitrogen (N): 2.27 moles / 2.27 moles = 1
The ratio of atoms in putrescine is C₂H₆N, which is the empirical formula.