Question

Sodium hydroxide (NaOH) and hydrochloric acid (HCI) combine to make table salt (NaCl) and water (H₂O). Which equation is balanced? (1 point)
NaOH + 2HCI - NaCl + H2O
NaOH + HCI NaCl + H₂O
2NaOH + HCI - NaCl + H₂O
2NaOH + 2HCI - 2NaCl + H₂O

Answer 1

To determine which equation is balanced, let's examine each option:

1. **NaOH + 2HCl → NaCl + H₂O**
- Left: 1 Na, 1 O, 2 Cl, 1 H (from NaOH and 2 HCl)
- Right: 1 Na, 1 Cl, 2 H, 1 O (from NaCl and H₂O)
- **Not balanced** (Cl is not balanced).

2. **NaOH + HCl → NaCl + H₂O**
- Left: 1 Na, 1 O, 1 Cl, 1 H (from NaOH and HCl)
- Right: 1 Na, 1 Cl, 2 H, 1 O (from NaCl and H₂O)
- **Not balanced** (H is not balanced).

3. **2NaOH + HCl → NaCl + H₂O**
- Left: 2 Na, 2 O, 1 Cl, 2 H (from 2 NaOH and HCl)
- Right: 1 Na, 1 Cl, 2 H, 1 O (from NaCl and H₂O)
- **Not balanced** (Na is not balanced).

4. **2NaOH + 2HCl → 2NaCl + 2H₂O**
- Left: 2 Na, 2 O, 2 Cl, 4 H (from 2 NaOH and 2 HCl)
- Right: 2 Na, 2 Cl, 4 H, 2 O (from 2 NaCl and 2 H₂O)
- **Balanced** (both sides have 2 Na, 2 Cl, 4 H, and 2 O).

Therefore, the balanced equation is:

**2NaOH + 2HCl → 2NaCl + 2H₂O**.