To complete and balance the acid-base equation HCl(aq) + Ba(OH)₂(aq) → ?, we first need to identify the reactants and what products they will generate. HCl is a strong acid and Ba(OH)₂ is a strong base, and when they react, they will undergo a neutralization reaction.
The products of this reaction are barium chloride (BaCl₂) and water (H₂O). The balanced equation for this reaction is:
HCl(aq) + Ba(OH)₂(aq) → BaCl₂(aq) + 2H₂O(l)
Now, let’s balance the equation. Starting with the left side, we have:
- 1 HCl provides 1 Cl and 1 H.
- Ba(OH)₂ provides 1 Ba, 2 OH, and 2 H.
On the right side:
- BaCl₂ provides 1 Ba and 2 Cl
- 2H₂O provides 2 H and 2 O
To achieve balance, we ensure that each type of atom is accounted for on both sides of the equation. Adding the necessary coefficients results in:
- 1 Ba (both sides),
- 2 Cl (from 2 HCl to match 1 BaCl₂),
- 4 H (2 from 2 HCl and 2 from Ba(OH)₂ to match 2 H₂O),
- 2 O (from 2 OH in Ba(OH)₂ to match 2 in 2 H₂O).
Thus, the final balanced equation indicates that 2 moles of HCl react with 1 mole of Ba(OH)₂ to produce 1 mole of BaCl₂ and 2 moles of water.