Which of the following chemical equations depicts a balanced chemical equation?

A. [tex]3 \text{AgNO}_3 + 2 \text{K}_2\text{CrO}_4 \rightarrow 3 \text{KNO}_3 + 2 \text{Ag}_2\text{CrO}_4[/tex]

B. [tex]\text{AgNO}_3 + \text{K}_2\text{CrO}_4 \rightarrow 2 \text{KNO}_3 + \text{Ag}_2\text{CrO}_4[/tex]

C. [tex]\text{AgNO}_3 + \text{K}_2\text{CrO}_4 \rightarrow \text{KNO}_3 + \text{Ag}_2\text{CrO}_4[/tex]

D. [tex]2 \text{AgNO}_3 + \text{K}_2\text{CrO}_4 \rightarrow 2 \text{KNO}_3 + \text{Ag}_2\text{CrO}_4[/tex]



Answer :

To determine which of the provided chemical equations is balanced, we need to compare the number of atoms of each element on both the reactant and product sides of the equation. A balanced chemical equation will have the same number of each type of atom on both sides.

Let's analyze each option step-by-step:

### Option A: [tex]\( 3 \, \text{AgNO}_3 + 2 \, \text{K}_2 \text{CrO}_4 \rightarrow 3 \, \text{KNO}_3 + 2 \, \text{Ag}_2 \text{CrO}_4 \)[/tex]

Reactants:
- [tex]\( \text{AgNO}_3 \)[/tex]: [tex]\( 3 \, \text{Ag} \)[/tex], [tex]\( 3 \, \text{NO}_3 \)[/tex]
- [tex]\( \text{K}_2 \text{CrO}_4 \)[/tex]: [tex]\( 4 \, \text{K} \)[/tex], [tex]\( 2 \, \text{CrO}_4 \)[/tex]
- Total: [tex]\( 3 \, \text{Ag} \)[/tex], [tex]\( 3 \, \text{NO}_3 \)[/tex], [tex]\( 4 \, \text{K} \)[/tex], [tex]\( 2 \, \text{CrO}_4 \)[/tex]

Products:
- [tex]\( \text{KNO}_3 \)[/tex]: [tex]\( 3 \, \text{K} \)[/tex], [tex]\( 3 \, \text{NO}_3 \)[/tex]
- [tex]\( \text{Ag}_2 \text{CrO}_4 \)[/tex]: [tex]\( 4 \, \text{Ag} \)[/tex], [tex]\( 2 \, \text{CrO}_4 \)[/tex]
- Total: [tex]\( 4 \, \text{Ag} \)[/tex], [tex]\( 3 \, \text{NO}_3 \)[/tex], [tex]\( 3 \, \text{K} \)[/tex], [tex]\( 2 \, \text{CrO}_4 \)[/tex]

The counts don't match: [tex]\( 3 \, \text{Ag} \neq 4 \, \text{Ag} \)[/tex] and [tex]\( 4 \, \text{K} \neq 3 \, \text{K} \)[/tex]. This equation is not balanced.

### Option B: [tex]\( \text{AgNO}_3 + \text{K}_2 \text{CrO}_4 \rightarrow 2 \, \text{KNO}_3 + \text{Ag}_2 \text{CrO}_4 \)[/tex]

Reactants:
- [tex]\( \text{AgNO}_3 \)[/tex]: [tex]\( 1 \, \text{Ag} \)[/tex], [tex]\( 1 \, \text{NO}_3 \)[/tex]
- [tex]\( \text{K}_2 \text{CrO}_4 \)[/tex]: [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]
- Total: [tex]\( 1 \, \text{Ag} \)[/tex], [tex]\( 1 \, \text{NO}_3 \)[/tex], [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]

Products:
- [tex]\( \text{KNO}_3 \)[/tex]: [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 2 \, \text{NO}_3 \)[/tex]
- [tex]\( \text{Ag}_2 \text{CrO}_4 \)[/tex]: [tex]\( 2 \, \text{Ag} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]
- Total: [tex]\( 2 \, \text{Ag} \)[/tex], [tex]\( 2 \, \text{NO}_3 \)[/tex], [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]

The counts don't match: [tex]\( 1 \, \text{Ag} \neq 2 \, \text{Ag} \)[/tex] and [tex]\( 1 \, \text{NO}_3 \neq 2 \, \text{NO}_3 \)[/tex]. This equation is not balanced.

### Option C: [tex]\( \text{AgNO}_3 + \text{K}_2 \text{CrO}_4 \rightarrow \text{KNO}_3 + \text{Ag}_2 \text{CrO}_4 \)[/tex]

Reactants:
- [tex]\( \text{AgNO}_3 \)[/tex]: [tex]\( 1 \, \text{Ag} \)[/tex], [tex]\( 1 \, \text{NO}_3 \)[/tex]
- [tex]\( \text{K}_2 \text{CrO}_4 \)[/tex]: [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]
- Total: [tex]\( 1 \, \text{Ag} \)[/tex], [tex]\( 1 \, \text{NO}_3 \)[/tex], [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]

Products:
- [tex]\( \text{KNO}_3 \)[/tex]: [tex]\( 1 \, \text{K} \)[/tex], [tex]\( 1 \, \text{NO}_3 \)[/tex]
- [tex]\( \text{Ag}_2 \text{CrO}_4 \)[/tex]: [tex]\( 2 \, \text{Ag} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]
- Total: [tex]\( 2 \, \text{Ag} \)[/tex], [tex]\( 1 \, \text{NO}_3 \)[/tex], [tex]\( 1 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]

The counts don't match: [tex]\( 1 \, \text{Ag} \neq 2 \, \text{Ag} \)[/tex] and [tex]\( 2 \, \text{K} \neq 1 \, \text{K} \)[/tex]. This equation is not balanced.

### Option D: [tex]\( 2 \, \text{AgNO}_3 + \text{K}_2 \text{CrO}_4 \rightarrow 2 \, \text{KNO}_3 + \text{Ag}_2 \text{CrO}_4 \)[/tex]

Reactants:
- [tex]\( \text{AgNO}_3 \)[/tex]: [tex]\( 2 \, \text{Ag} \)[/tex], [tex]\( 2 \, \text{NO}_3 \)[/tex]
- [tex]\( \text{K}_2 \text{CrO}_4 \)[/tex]: [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]
- Total: [tex]\( 2 \, \text{Ag} \)[/tex], [tex]\( 2 \, \text{NO}_3 \)[/tex], [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]

Products:
- [tex]\( \text{KNO}_3 \)[/tex]: [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 2 \, \text{NO}_3 \)[/tex]
- [tex]\( \text{Ag}_2 \text{CrO}_4 \)[/tex]: [tex]\( 2 \, \text{Ag} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]
- Total: [tex]\( 2 \, \text{Ag} \)[/tex], [tex]\( 2 \, \text{NO}_3 \)[/tex], [tex]\( 2 \, \text{K} \)[/tex], [tex]\( 1 \, \text{CrO}_4 \)[/tex]

The counts match: [tex]\( 2 \, \text{Ag} = 2 \, \text{Ag} \)[/tex], [tex]\( 2 \, \text{NO}_3 = 2 \, \text{NO}_3 \)[/tex], [tex]\( 2 \, \text{K} = 2 \, \text{K} \)[/tex], and [tex]\( 1 \, \text{CrO}_4 = 1 \, \text{CrO}_4 \)[/tex]. This equation is balanced.

Answer: Option D: [tex]\( 2 \, \text{AgNO}_3 + \text{K}_2 \text{CrO}_4 \rightarrow 2 \, \text{KNO}_3 + \text{Ag}_2 \text{CrO}_4 \)[/tex]