Ascorbic acid is a compound containing of three element C,H, and O when a 0.214g sample is burned in oxyzen 0.320g of CO2 and 0.0874g H2O are formed. What is the Empirical formula of ascorbic acid?
Convert g CO2 to g C.
0.320 g CO2 x (12/44) = ?
Convert g H2O to g H.
0.0874 x (2/18) = ?
Then g O = 0.214 - g C - g H.
% C = [g C/0.214]*100 = ?
% O = [g O/0.214]*100 = ?
% H = [g H/0.214]*100 = ?
Now take 100 g sample which will give you those percentages as g C, H, O.
Convert to mols by
mols C = g C/12 = ?
mols H = g H/1 = ?
mols O = g O/16 = ?
Find the whole number ratio of these elements to each other. The easy way to do that is to divide the smallest number by itself; the divide the other number by the same small number. Post your work if you run into troble.
To determine the empirical formula of ascorbic acid, we need to find the ratio of the elements present in the compound.
First, let's calculate the moles of carbon dioxide (CO2) and water (H2O) produced.
Molar mass of CO2:
C: 12.01 g/mol
O: 16.00 g/mol
Total molar mass of CO2 = 12.01 g/mol + (2 × 16.00 g/mol) = 44.01 g/mol
Moles of CO2 = mass of CO2 / molar mass of CO2 = 0.320 g / 44.01 g/mol
Molar mass of H2O:
H: 1.01 g/mol
O: 16.00 g/mol
Total molar mass of H2O = (2 × 1.01 g/mol) + 16.00 g/mol = 18.02 g/mol
Moles of H2O = mass of H2O / molar mass of H2O = 0.0874 g / 18.02 g/mol
Next, let's calculate the moles of carbon (C), hydrogen (H), and oxygen (O) in the sample.
Moles of C = (moles of CO2) × 1 (since there is 1 mole of carbon in 1 mole of CO2)
Moles of H = (moles of H2O) × 2 (since there are 2 moles of hydrogen in 1 mole of H2O)
Moles of O = (moles of CO2) × 2 (since there are 2 moles of oxygen in 1 mole of CO2) + (moles of H2O) × 1 (since there is 1 mole of oxygen in 1 mole of H2O)
Now, divide the moles of each element by the smallest number of moles calculated to obtain the simplest whole-number ratio.
Simplify the ratio if possible to get the empirical formula of ascorbic acid.
To determine the empirical formula of ascorbic acid, we need to find the ratio of the elements present in the compound. Using the given information, we can calculate the empirical formula step by step:
1. Calculate the number of moles of CO2 produced:
- The molar mass of CO2 (carbon dioxide) = 12.01 g/mol + (2 × 16.00 g/mol) = 44.01 g/mol
- Moles of CO2 = mass of CO2 / molar mass of CO2
= 0.320 g / 44.01 g/mol
2. Calculate the number of moles of H2O produced:
- The molar mass of H2O (water) = 2 × 1.01 g/mol + 16.00 g/mol = 18.02 g/mol
- Moles of H2O = mass of H2O / molar mass of H2O
= 0.0874 g / 18.02 g/mol
3. Calculate the number of moles of carbon:
- From the combustion, CO2 comes from carbon in the ascorbic acid compound.
- Moles of carbon = moles of CO2
4. Calculate the number of moles of hydrogen:
- From the combustion, H2O comes from hydrogen in the ascorbic acid compound.
- Moles of hydrogen = moles of H2O
5. Calculate the number of moles of oxygen:
- Total moles of oxygen = (moles of CO2 × 2) + moles of H2O
- This is because each molecule of CO2 contains 2 oxygen atoms.
- Moles of oxygen = (moles of CO2 × 2) + moles of H2O
6. Find the empirical formula:
- Divide the moles of each element by the smallest number of moles obtained in steps 3, 4, and 5.
- Round the obtained ratios to the nearest whole number.
- This will give you the subscripts (or ratios) needed for the empirical formula.
After completing these calculations, you should have the ratios of carbon, hydrogen, and oxygen. The empirical formula of ascorbic acid will be represented by these ratios.