In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?
The problem is flawed. 18 g C can produce ONLY 66 g CO2.
18g
To find the mass of oxygen needed in the reaction, we need to first determine the molar ratio between carbon and oxygen in the reaction.
1. Find the molar mass of carbon (C):
- The atomic mass of carbon (C) is approximately 12 g/mol.
2. Find the molar mass of carbon dioxide (CO2):
- The atomic mass of carbon (C) is approximately 12 g/mol.
- The atomic mass of oxygen (O) is approximately 16 g/mol.
- The molar mass of carbon dioxide (CO2) is therefore (12 g/mol + 2 * 16 g/mol) = 44 g/mol.
3. Calculate the moles of carbon (C):
- Divide the given mass of carbon (18 g) by the molar mass of carbon (12 g/mol):
18 g / 12 g/mol = 1.5 moles of carbon.
4. Calculate the moles of carbon dioxide (CO2):
- Divide the given mass of carbon dioxide (72 g) by the molar mass of carbon dioxide (44 g/mol):
72 g / 44 g/mol ≈ 1.64 moles of carbon dioxide.
5. Determine the molar ratio between carbon (C) and oxygen (O) in the reaction:
- From the balanced chemical equation C + O2 → CO2, we can see that the ratio is 1:1.
- This means that for every 1 mole of carbon dioxide produced, we need 1 mole of oxygen.
6. Calculate the moles of oxygen (O):
- Since the molar ratio between carbon dioxide and oxygen is 1:1, we know that the moles of oxygen required will be the same as the moles of carbon dioxide.
- Therefore, the moles of oxygen needed in the reaction are also 1.64 moles.
7. Calculate the mass of oxygen (O):
- Multiply the moles of oxygen (1.64 moles) by the molar mass of oxygen (16 g/mol):
1.64 moles * 16 g/mol = 26.24 g.
Therefore, 26.24 grams of oxygen would be needed in the reaction.
Keep in mind that the given mass of carbon (18 g) and the resulting mass of carbon dioxide (72 g) are provided to help determine the molar ratios, but they are not directly used to calculate the mass of oxygen needed.