Question

One half of a balanced chemical equation is shown.

3Mg(OH)2 + 2H3PO4

Which lists the numbers of each atom the other half of the equation would contain?

3 Mg, 2 P, 14 O, 12 H
Mg, 2 P, 14 O, 6 H
3 Mg, 8 P, 7 O, 6 H
6 Mg, 6 P, 2 O, 12 H

Answer 1

To determine the quantities of atoms in the other half of the balanced chemical equation for the reaction involving magnesium hydroxide (Mg(OH)₂) and phosphoric acid (H₃PO₄), we need to account for the number of each type of atom contributed by the reactants.

1. **Reactants:**
- From 3 Mg(OH)₂:
- Magnesium (Mg): 3
- Oxygen (O): 3 × 2 = 6 (because each Mg(OH)₂ has 2 oxygen atoms)
- Hydrogen (H): 3 × 2 = 6 (because each Mg(OH)₂ has 2 hydrogen atoms)

- From 2 H₃PO₄:
- Hydrogen (H): 2 × 3 = 6
- Phosphorus (P): 2 × 1 = 2
- Oxygen (O): 2 × 4 = 8 (because each H₃PO₄ has 4 oxygen atoms)

2. **Total from reactants:**
- Magnesium (Mg): 3
- Phosphorus (P): 2
- Oxygen (O): 6 (from Mg(OH)₂) + 8 (from H₃PO₄) = 14
- Hydrogen (H): 6 (from Mg(OH)₂) + 6 (from H₃PO₄) = 12

3. **Product side:**
From the original equation provided, we conclude that the total number of atoms must equal the product side.

Therefore, the other half of the balanced equation must have:
- 3 Mg
- 2 P
- 14 O
- 12 H

Thus, the correct answer is:

**3 Mg, 2 P, 14 O, 12 H**