A sample of liquid consisting of only C,H and O and having a mass of 0.5438g was burned in pure oxygen and 1.039g of CO2 and 0.6369g H2O were obtained. what is the empirical formula of the compound?
12g/molC / 44g/molCO2 = x / 1.039g CO2
12/44 (1.039) = 0.2834 g C
2g/mol H2 / 18g/molH2O = x / 0.6369gH2O
2/18 (0.6369) = 0.071 g H
0.5438 - 0.2834 - 0.071 = 0.1939 g O
0.2824gC/12g/molC = 0.0236 mol C
0.071gH / 1g/molH = 0.071 mol H
0.1939gO/16g/molO = 0.0121 mol O
Divide each of these numbers by lowest moles.
0.0236/0.0121 = 2
0.071/0.0121 = 6
0.0121/0.0121 = 1
This number represents the ratio of each element (the subscript of each)
Therefore empirical formula = C2H6O
C2H6O
To determine the empirical formula of the compound, we need to find the ratio of atoms of each element in the compound.
1. Start by calculating the number of moles of CO2 and H2O obtained.
Number of moles of CO2 = mass of CO2 / molar mass of CO2
Number of moles of CO2 = 1.039g / 44.01g/mol = 0.0236 mol
Number of moles of H2O = mass of H2O / molar mass of H2O
Number of moles of H2O = 0.6369g / 18.02g/mol = 0.0354 mol
2. Determine the number of moles of carbon (C) and hydrogen (H) in the original compound.
Since there is only one carbon atom in each molecule of CO2 and one hydrogen atom in each molecule of H2O, the number of moles of carbon and hydrogen will be the same as the number of moles of CO2 and H2O, respectively.
Number of moles of C = 0.0236 mol
Number of moles of H = 0.0354 mol
3. Calculate the mass of carbon (C), hydrogen (H), and oxygen (O) in the original compound.
Mass of C = number of moles of C * molar mass of C
Mass of C = 0.0236 mol * 12.01 g/mol = 0.2829 g
Mass of H = number of moles of H * molar mass of H
Mass of H = 0.0354 mol * 1.01 g/mol = 0.0358 g
Mass of O = Mass of the original sample - (mass of C + mass of H)
Mass of O = 0.5438 g - (0.2829 g + 0.0358 g) = 0.2251 g
4. Calculate the mole ratio of C, H, and O atoms.
The mole ratio can be found by dividing the number of moles of each element by the smallest number of moles, which in this case is the number of moles of carbon.
Mole ratio of C = 0.0236 mol / 0.0236 mol = 1
Mole ratio of H = 0.0354 mol / 0.0236 mol = 1.5
Mole ratio of O = 0.2251 g / 0.0236 mol = 9.53
5. Convert the mole ratios to whole numbers by multiplying them by the smallest whole number that gives the closest integers.
Mole ratio of C = 1
Mole ratio of H = 1.5 * 2 = 3
Mole ratio of O = 9.53 * 2 = 19 (approximately)
6. Write the empirical formula using the whole number ratios.
The empirical formula of the compound is CH3O19 (approximately), but we need to simplify it further.
7. Divide all the subscripts by the greatest common divisor (GCD) to obtain the simplest whole-number ratio.
The GCD of 1, 3, and 19 is 1 (since they are already relatively prime).
Final empirical formula: CH3O19
Please note that the empirical formula obtained may not be a realistic representation of a compound, as compounds generally have simpler formulas. It is possible that there was an error in the experimental procedure or calculation.
To determine the empirical formula of the compound, we need to find the ratio of the elements present in the compound.
First, let's calculate the moles of CO2 and H2O obtained:
1. Convert the mass of CO2 to moles:
- Mass of CO2 = 1.039 g
- Molar mass of CO2 = 12.01 g/mol (C) + 2 * 16.00 g/mol (O) = 44.01 g/mol
- Moles of CO2 = Mass of CO2 / Molar mass of CO2 = 1.039 g / 44.01 g/mol
2. Convert the mass of H2O to moles:
- Mass of H2O = 0.6369 g
- Molar mass of H2O = 2 * 1.01 g/mol (H) + 16.00 g/mol (O) = 18.02 g/mol
- Moles of H2O = Mass of H2O / Molar mass of H2O = 0.6369 g / 18.02 g/mol
Next, we need to find the ratio of C, H, and O in the compound.
1. Calculate the moles of C:
- Moles of C = Moles of CO2 (since each CO2 molecule contains one C atom)
2. Calculate the moles of H:
- Moles of H = 2 * Moles of H2O (since each H2O molecule contains two H atoms)
3. Calculate the moles of O:
- Moles of O = Moles of CO2 + Moles of H2O (since CO2 contains two O atoms and each H2O contains one O atom)
Finally, we need to find the smallest whole number ratio of C, H, and O. Divide each of the moles by the smallest number of moles among them.
This calculation will give you the empirical formula of the compound, representing the simplest whole number ratio of the elements.