19.026 g
The reaction between D₂ and O₂ is given by the equation;
2D₂(g) + O₂(g) → 2H₂O(l)
We are given;
Mass of oxygen (O₂) that reacted as 7.60 g
We are required to calculate the mass of D₂O produced;
To calculate the number of moles we divide mass by the molar mass.
Moles = mass ÷ Molar mass
Molar mass of O₂ is 16.0 g/mol
Therefore;
Moles = 7.60 g ÷ 16.0 g/mol
= 0.475 moles
From the equation, 1 mole of oxygen reacts to produce 2 moles of D₂O
Thus, the mole ratio of O₂ : D₂O is 1 : 2
Therefore, moles of D₂O = Moles of O₂ × 2
= 0.475 moles × 2
= 0.95 moles
Mass = Number of moles × Molar mass
Molar mass of heavy water = 20.0276 g/mol
Therefore;
Mass of heavy water = 0.95 moles × 20.0276 g/mol
= 19.026 g
Hence, the mass of heavy water produced is 19.026 g