Final answer:
By subtracting the mass of hydrogen from the mass of water produced, we find that 183.8 g of oxygen reacted with the hydrogen, making answer A the correct choice.
Step-by-step explanation:
When 23.2 g of hydrogen is burned to produce 207 g of water, we want to determine the mass of oxygen that reacted. From the given chemical equation 2H₂ + O₂ → 2H₂O, it is understood that 2 moles of hydrogen react with 1 mole of oxygen to form 2 moles of water. By using the molar masses of hydrogen (H₂ = 2.02 g/mol) and oxygen (O₂ = 32.0 g/mol), we can calculate the mass of oxygen that reacted.
To find the amount of oxygen, we subtract the mass of hydrogen used from the mass of water produced: 207 g (mass of H₂O) - 23.2 g (mass of H₂) gives us the mass of oxygen that reacted with hydrogen. This results in 183.8 g of O₂, which means Answer A is the correct choice.