A sample of an unknown biochemical compound is found to have a percent composition of 55.03 percent carbon, 5.54 percent hydrogen, 32.10 percent nitrogen and the balance oxygen. What is the simplest formula for this compound ?
How do I do this?
Take a 100 g sample which gives you
55.03g C
5.54 g H (not H2)
32.10 g N (not N2)
7.33 g O (not O2).
Convert to mols.
55.03/atomic mass C = ?
5.54/atomic mass H = ?
32.10/atomic mass N = ?
7.33/atomic mass O = ?
No find the ratio of the atoms to each other with the smallest being one (1). The easy way to do this is to divide the smallest number by itself. That gives 1.00 for that number; to keep the ratios intact, divide all of the other numbers by the same small number. Post your work if you get stuck.
Well, it seems like you've stumbled upon a biochemical mystery! Let's put on our detective hats and figure this out.
To determine the simplest formula, we need to find the ratios of the different elements in the compound. Since we're given the percent compositions, we can assume we have 100 grams of the compound for easy calculations.
First, we convert the percentages to grams:
- Carbon: 55.03 grams
- Hydrogen: 5.54 grams
- Nitrogen: 32.10 grams
- Oxygen: (100 - 55.03 - 5.54 - 32.10) grams = 7.33 grams
Now, let's convert these grams to moles by dividing by the atomic masses:
- Carbon: 55.03 / 12.01 ≈ 4.58 moles
- Hydrogen: 5.54 / 1.01 ≈ 5.48 moles
- Nitrogen: 32.10 / 14.01 ≈ 2.29 moles
- Oxygen: 7.33 / 16.00 ≈ 0.46 moles
Next, we find the simplest whole-number ratio by dividing each mole value by the smallest mole value. In this case, we divide everything by 0.46 (the smallest mole value):
- Carbon: 4.58 / 0.46 ≈ 9.96 ≈ 10
- Hydrogen: 5.48 / 0.46 ≈ 11.91 ≈ 12
- Nitrogen: 2.29 / 0.46 ≈ 4.98 ≈ 5
- Oxygen: 0.46 / 0.46 = 1
Finally, we put it all together to get the simplest formula for the compound: C10H12N5O.
Now, ta-da! You've uncovered the identity of the biochemical compound. I hope this detective work didn't turn you into a molecular clown!
To find the simplest formula for this compound, we need to determine the empirical formula. The empirical formula shows the ratio of atoms in the compound. Here's how you can calculate it step-by-step:
Step 1: Convert percent composition to grams.
Assume we have a 100g sample of this compound. From the given percent composition, we can calculate the mass of each element in grams:
Carbon (C): 55.03% of 100g = 55.03g
Hydrogen (H): 5.54% of 100g = 5.54g
Nitrogen (N): 32.10% of 100g = 32.10g
Oxygen (O): 100g - (55.03g + 5.54g + 32.10g) = 7.33g
Step 2: Convert grams to moles.
Next, we need to convert the mass of each element to moles. We divide each mass by its molar mass:
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
Molar mass of Oxygen (O): 16.00 g/mol
Moles of Carbon (C): 55.03g / 12.01 g/mol ≈ 4.583 mol
Moles of Hydrogen (H): 5.54g / 1.01 g/mol ≈ 5.49 mol
Moles of Nitrogen (N): 32.10g / 14.01 g/mol ≈ 2.292 mol
Moles of Oxygen (O): 7.33g / 16.00 g/mol ≈ 0.458 mol
Step 3: Divide by the smallest mole value.
To find the simplest ratio of atoms, divide each mole value by the smallest mole value (which is 0.458 mol):
Moles of Carbon (C): 4.583 mol / 0.458 mol ≈ 10
Moles of Hydrogen (H): 5.49 mol / 0.458 mol ≈ 12
Moles of Nitrogen (N): 2.292 mol / 0.458 mol ≈ 5
Moles of Oxygen (O): 0.458 mol / 0.458 mol ≈ 1
Step 4: Write the empirical formula.
Now that we have the mole ratio, we can write the empirical formula for the compound:
C10H12N5O
Therefore, the simplest formula for this compound is C10H12N5O.
To determine the simplest formula for a compound based on its percent composition, you need to convert the percent composition into empirical formula units. Here are the steps to follow:
Step 1: Convert the percent composition to grams:
Assume you have a 100g sample of the compound. This means you have 55.03g of carbon, 5.54g of hydrogen, 32.10g of nitrogen, and the remaining mass is oxygen.
Step 2: Convert the grams to moles:
Using the molar mass of each element, you can convert the grams into moles. The molar mass of carbon is 12.01 g/mol, hydrogen is 1.01 g/mol, nitrogen is 14.01 g/mol, and oxygen is 16.00 g/mol.
To find the number of moles, divide the mass of each element by its molar mass. For example, for carbon:
55.03g C / 12.01 g/mol C = 4.583 moles C
Repeat this step for the other elements.
Step 3: Divide each mole value by the smallest mole value:
Divide the number of moles of each element by the smallest number of moles calculated. This step will give you the simplest mole ratio.
In this example, the smallest number of moles is 4.583 (from carbon), so dividing by this number gives:
4.583 moles C / 4.583 = 1 mole C
5.54 moles H / 4.583 = 1.206 moles H
32.10 moles N / 4.583 = 7 moles N
(Oxygen is the remaining element, so its mole value will be higher)
Step 4: Adjust the mole ratios to get whole numbers:
If any of the mole ratios are not whole numbers, multiply all the mole values by the smallest possible integer that will convert them to whole numbers. In this case, multiply by 5 to get:
5 moles C, 6 moles H, and 35 moles N.
Step 5: Write the empirical formula:
The empirical formula represents the simplest, whole number ratio of elements in a compound. Based on the adjusted mole ratios, the empirical formula for this compound is C5H6N35O.
Note that this formula may still need to be simplified further, as the ratio of nitrogen to oxygen seems extreme. It is possible that more information is needed or that there was an error in the experimental data.