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

1 answer

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.