In the chemical equation 2HCl + Na2O → xNaCl + H2O, what value of x will balance the equation?

• A. 4
• B. 3
• C. 2
• D. 1

Answer: (C)

Verified step by step guidance

1. Write down the unbalanced chemical equation: \$2HCl + Na_2O \rightarrow xNaCl + H_2O$.
2. Identify the number of atoms of each element on the reactant side: Hydrogen (H) = 2 (from 2 HCl), Chlorine (Cl) = 2 (from 2 HCl), Sodium (Na) = 2 (from Na_2O), Oxygen (O) = 1 (from Na_2O).
3. Balance the sodium (Na) atoms first. Since there are 2 Na atoms in Na_2O, you need 2 NaCl units on the product side to have 2 Na atoms: \(x = 2\).
4. Check the chlorine (Cl) atoms: 2 Cl atoms on the reactant side (from 2 HCl) and 2 Cl atoms on the product side (from 2 NaCl), so chlorine is balanced.
5. Check the hydrogen (H) and oxygen (O) atoms: 2 H atoms on the reactant side (from 2 HCl) and 2 H atoms on the product side (from H_2O), and 1 O atom on both sides, so hydrogen and oxygen are balanced.