Provided here is an unbalanced chemical equation. CuCl
- Na
PO
? Cu
(PO
) - NaCl Which of the following shows the product side of the correctly balanced equation? ?4Cu
(PO
) - 2NaCl ?2Cu
(PO
) - 3NaCl ?Cu
(PO
) - 6NaCl ?3Cu
(PO
) - NaCl
The Correct Answer and Explanation is:
Given unbalanced equation: CuCl+Na3PO4→Cu3(PO4)2+NaCl\text{CuCl} + \text{Na}_3\text{PO}_4 \rightarrow \text{Cu}_3(\text{PO}_4)_2 + \text{NaCl}CuCl+Na3PO4→Cu3(PO4)2+NaCl
Balancing the equation:
- Identify reactants and products:
- Reactants: Copper(I) chloride (CuCl), Sodium phosphate (Na₃PO₄)
- Products: Copper(II) phosphate (Cu₃(PO₄)₂), Sodium chloride (NaCl)
- Balance copper (Cu):
- On product side: Cu3(PO4)2\text{Cu}_3(\text{PO}_4)_2Cu3(PO4)2 contains 3 Cu atoms.
- On reactant side: We need 3 CuCl to provide 3 Cu atoms.
3CuCl+Na3PO4→Cu3(PO4)2+NaCl3\text{CuCl} + \text{Na}_3\text{PO}_4 \rightarrow \text{Cu}_3(\text{PO}_4)_2 + \text{NaCl}3CuCl+Na3PO4→Cu3(PO4)2+NaCl
- Balance sodium (Na):
- Na3PO4\text{Na}_3\text{PO}_4Na3PO4 has 3 Na atoms.
- On the product side, we need 3 NaCl to balance Na.
3CuCl+Na3PO4→Cu3(PO4)2+3NaCl3\text{CuCl} + \text{Na}_3\text{PO}_4 \rightarrow \text{Cu}_3(\text{PO}_4)_2 + 3\text{NaCl}3CuCl+Na3PO4→Cu3(PO4)2+3NaCl
- Check phosphorus (P) and chlorine (Cl):
- Phosphorus is already balanced (1 phosphate group on both sides).
- Chlorine: 3 Cl on both sides.
The final balanced equation is: 3CuCl+Na3PO4→Cu3(PO4)2+3NaCl3\text{CuCl} + \text{Na}_3\text{PO}_4 \rightarrow \text{Cu}_3(\text{PO}_4)_2 + 3\text{NaCl}3CuCl+Na3PO4→Cu3(PO4)2+3NaCl
Correct product side:
Cu3(PO4)2+3NaCl\text{Cu}_3(\text{PO}_4)_2 + 3\text{NaCl}Cu3(PO4)2+3NaCl
From the options provided, the correct answer is:
3Cu(PO₄)₂ + NaCl
→ This is incorrect formatting. The correct answer according to options should be:
Cu₃(PO₄)₂ + 3NaCl
Textbook-style explanation
Balancing Chemical Reactions: An Example with Copper(I) Chloride and Sodium Phosphate
In chemical reactions, the law of conservation of mass states that matter cannot be created or destroyed. Therefore, the number of atoms for each element must be the same on both the reactant and product sides of a chemical equation. Let us apply this principle to balance the given reaction:
Unbalanced equation: CuCl+Na3PO4→Cu3(PO4)2+NaCl\text{CuCl} + \text{Na}_3\text{PO}_4 \rightarrow \text{Cu}_3(\text{PO}_4)_2 + \text{NaCl}CuCl+Na3PO4→Cu3(PO4)2+NaCl
First, examine the copper atoms. The product Cu3(PO4)2\text{Cu}_3(\text{PO}_4)_2Cu3(PO4)2 contains 3 copper atoms. To balance this, place the coefficient 3 before CuCl: 3CuCl+Na3PO4→Cu3(PO4)2+NaCl3\text{CuCl} + \text{Na}_3\text{PO}_4 \rightarrow \text{Cu}_3(\text{PO}_4)_2 + \text{NaCl}3CuCl+Na3PO4→Cu3(PO4)2+NaCl
Next, balance the sodium atoms. Sodium phosphate (Na3PO4\text{Na}_3\text{PO}_4Na3PO4) contains 3 sodium atoms. Therefore, place a coefficient of 3 before NaCl to ensure the sodium atoms are balanced: 3CuCl+Na3PO4→Cu3(PO4)2+3NaCl3\text{CuCl} + \text{Na}_3\text{PO}_4 \rightarrow \text{Cu}_3(\text{PO}_4)_2 + 3\text{NaCl}3CuCl+Na3PO4→Cu3(PO4)2+3NaCl
Upon verification, phosphorus and chlorine atoms are also balanced. Each side contains 1 phosphate group and 3 chlorine atoms.
Thus, the correctly balanced equation is: 3CuCl+Na3PO4→Cu3(PO4)2+3NaCl3\text{CuCl} + \text{Na}_3\text{PO}_4 \rightarrow \text{Cu}_3(\text{PO}_4)_2 + 3\text{NaCl}3CuCl+Na3PO4→Cu3(PO4)2+3NaCl
The correctly balanced product side is: Cu3(PO4)2+3NaCl\text{Cu}_3(\text{PO}_4)_2 + 3\text{NaCl}Cu3(PO4)2+3NaCl
This ensures the conservation of mass and confirms the reaction is properly balanced.
