How many dozens of silver atoms are in the piece of jewelry?.

3.57 × 10⁵ mol O₂

7.13 × 10⁵ mol H₂O

Explanation:

Step 1: Write the balanced equation

2 H₂ + O₂ ⇒ 2 H₂O

Step 2: Calculate the moles corresponding to 1.44 × 10⁶ g of hydrogen

The molar mass of hydrogen is 2.02 g/mol.

1.44 × 10⁶ g × (1 mol/2.02 g) = 7.13 × 10⁵ mol

Step 3: Calculate the moles of oxygen needed to react with 7.13 × 10⁵ moles of hydrogen

The molar ratio of H₂ to O₂ is 2:1. The reacting moles of oxygen are 1/2 × 7.13 × 10⁵ mol = 3.57 × 10⁵ mol.

Step 4: Calculate the moles of water produced from 7.13 × 10⁵ moles of hydrogen

The molar ratio of H₂ to H₂O is 2:2. The moles of water formed are 2/2 × 7.13 × 10⁵ mol = 7.13 × 10⁵ mol.