Hydrocarbon burn in excess oxygen yields 4.4g of carbon(iv)oxide and 2 of 7g of water. Find the empirical formula of hydrocarbon
To find the empirical formula of the hydrocarbon, we need to determine the ratio of carbon to hydrogen in the compound.
1. Calculate the moles of carbon dioxide (CO2) produced:
- Mass of carbon dioxide = 4.4 g
- Molar mass of carbon dioxide (CO2) = 44 g/mol (12 g/mol for carbon + 16 g/mol for oxygen x 2)
- Moles of carbon dioxide = mass / molar mass = 4.4 g / 44 g/mol = 0.1 mol
2. Calculate the moles of water (H2O) produced:
- Mass of water = 7 g
- Molar mass of water (H2O) = 18 g/mol (2 g/mol for hydrogen + 16 g/mol for oxygen)
- Moles of water = mass / molar mass = 7 g / 18 g/mol = 0.39 mol
3. Determine the moles of carbon and hydrogen atoms in the hydrocarbon:
- Since the hydrocarbon burns to produce carbon dioxide (CO2) and water (H2O), the carbon in the hydrocarbon becomes carbon dioxide and the hydrogen becomes water.
- The ratio of carbon dioxide to carbon atoms is 1:1, so the moles of carbon atoms in the hydrocarbon is also 0.1 mol.
- The ratio of water to hydrogen atoms is 2:1, so the moles of hydrogen atoms in the hydrocarbon is 0.39 mol x 2 = 0.78 mol.
4. Divide the moles of carbon and hydrogen by the smaller value:
- Moles of carbon atoms = 0.1 mol / 0.1 mol = 1
- Moles of hydrogen atoms = 0.78 mol / 0.1 mol = 7.8
5. Round the mole ratio to the nearest whole number:
- The ratio is approximately 1:8 (carbon to hydrogen)
Therefore, the empirical formula of the hydrocarbon is CH8.
To find the empirical formula of the hydrocarbon, we need to determine the simplest whole-number ratio of atoms in the compound.
1. Start by determining the moles of each product formed.
- The moles of carbon dioxide (CO2) can be calculated using its molar mass. The molar mass of carbon dioxide is the sum of the molar mass of carbon (12.01 g/mol) and oxygen (16.00 g/mol) multiplied by the number of atoms of each element.
Moles of CO2 = mass of CO2 / molar mass of CO2
= 4.4 g / (12.01 g/mol + 2 * 16.00 g/mol)
- The moles of water (H2O) can also be calculated similarly. The molar mass of water is the sum of the molar mass of hydrogen (1.01 g/mol) and oxygen (16.00 g/mol) multiplied by the number of atoms of each element.
Moles of H2O = mass of H2O / molar mass of H2O
= 7g / (2 * 1.01 g/mol + 16.00 g/mol)
2. Next, determine the simplest whole-number ratio of moles of carbon, hydrogen, and oxygen atoms.
- Divide the moles of carbon dioxide and water by their respective smallest number of moles to find the simplest ratio of atoms.
Carbon atoms: Moles of CO2 / smallest number of moles of CO2 and H2O
Hydrogen atoms: Moles of H2O / smallest number of moles of CO2 and H2O
Oxygen atoms: [(Moles of CO2 + Moles of H2O) - 2*(Number of carbon atoms) - 2*(Number of hydrogen atoms)] / 2
3. Finally, use the obtained whole-number ratio of atoms to write the empirical formula of the hydrocarbon.
The empirical formula represents the simplest, whole-number ratio of atoms present in the compound.
Please provide the moles calculated for CO2 and H2O, and I can help you calculate the empirical formula of the hydrocarbon.