This formula equation is unbalanced.
[tex]\[ BaCl_2 (aq) + Na_2CO_3 (aq) \rightarrow BaCO_3 (s) + NaCl (aq) \][/tex]

Which coefficient should be placed in front of [tex]\[ NaCl \][/tex] to balance this equation?

A. 1
B. 2
C. 3
D. 4



Answer :

To balance the given chemical equation:

[tex]\[ \text{BaCl}_2(aq) + \text{Na}_2\text{CO}_3(aq) \rightarrow \text{BaCO}_3(s) + \text{NaCl}(aq) \][/tex]

we proceed with the following steps:

1. Write down the number of atoms of each element on both sides of the equation:

- Reactants:
[tex]\[ \text{BaCl}_2(aq) + \text{Na}_2\text{CO}_3(aq) \][/tex]
- Barium (Ba): 1
- Chlorine (Cl): 2
- Sodium (Na): 2
- Carbon (C): 1
- Oxygen (O): 3

- Products:
[tex]\[ \text{BaCO}_3(s) + \text{NaCl}(aq) \][/tex]
- Barium (Ba): 1
- Chlorine (Cl): 1
- Sodium (Na): 1
- Carbon (C): 1
- Oxygen (O): 3

2. Compare the number of atoms of each element on both sides of the equation to identify the imbalance:

- Barium (Ba): 1 (Reactants) vs. 1 (Products) → Balanced
- Chlorine (Cl): 2 (Reactants) vs. 1 (Products) → Not balanced
- Sodium (Na): 2 (Reactants) vs. 1 (Products) → Not balanced
- Carbon (C): 1 (Reactants) vs. 1 (Products) → Balanced
- Oxygen (O): 3 (Reactants) vs. 3 (Products) → Balanced

3. Balance the elements that are not balanced by adjusting the coefficients:

Since there are 2 Cl atoms and 2 Na atoms on the reactants side and only 1 of each on the products side, we can balance the equation by placing the coefficient 2 in front of NaCl on the products side:

[tex]\[ \text{BaCl}_2(aq) + \text{Na}_2\text{CO}_3(aq) \rightarrow \text{BaCO}_3(s) + 2 \text{NaCl}(aq) \][/tex]

4. Verify the balance:

- Reactants:
[tex]\[ \text{BaCl}_2(aq) + \text{Na}_2\text{CO}_3(aq) \][/tex]
- Barium (Ba): 1
- Chlorine (Cl): 2
- Sodium (Na): 2
- Carbon (C): 1
- Oxygen (O): 3

- Products:
[tex]\[ \text{BaCO}_3(s) + 2 \text{NaCl}(aq) \][/tex]
- Barium (Ba): 1
- Chlorine (Cl): 2
- Sodium (Na): 2
- Carbon (C): 1
- Oxygen (O): 3

Now, all elements are balanced on both sides of the equation.

Therefore, the coefficient that should be placed in front of [tex]\(\text{NaCl}\)[/tex] to balance the equation is:

[tex]\[ \boxed{2} \][/tex]