Question

_ Na2O + _ CaBr2 → _ NaBr + _ CaO

a
1:2:1:1
b
2:1:1:1
c
1:1:2:1
d
1:1:1:2

Answer 1

To balance the chemical equation \( \text{Na}_2\text{O} + \text{CaBr}_2 \rightarrow \text{NaBr} + \text{CaO} \), we can follow these steps:

1. **Identify the components:**
- Reactants: \( \text{Na}_2\text{O} \) and \( \text{CaBr}_2 \)
- Products: \( \text{NaBr} \) and \( \text{CaO} \)

2. **Write the unbalanced equation:**
\[ \text{Na}_2\text{O} + \text{CaBr}_2 \rightarrow \text{NaBr} + \text{CaO} \]

3. **Count the atoms of each element on both sides:**
- Left Side:
- Na: 2 (from \( \text{Na}_2\text{O} \))
- O: 1 (from \( \text{Na}_2\text{O} \))
- Ca: 1 (from \( \text{CaBr}_2 \))
- Br: 2 (from \( \text{CaBr}_2 \))

- Right Side (initially):
- Na: 1 (from \( \text{NaBr} \))
- O: 1 (from \( \text{CaO} \))
- Ca: 1 (from \( \text{CaO} \))
- Br: 1 (from \( \text{NaBr} \))

4. **Balance the reactants and products:**
- To balance Na, since there are 2 Na in the reactants but only 1 in the products, we place a coefficient of 2 in front of \( \text{NaBr} \):
\[ \text{Na}_2\text{O} + \text{CaBr}_2 \rightarrow 2 \text{NaBr} + \text{CaO} \]

5. **Recount the atoms after this adjustment:**
- Left Side:
- Na: 2
- O: 1
- Ca: 1
- Br: 2

- Right Side:
- Na: 2 (from \( 2 \, \text{NaBr} \))
- O: 1 (from \( \text{CaO} \))
- Ca: 1 (from \( \text{CaO} \))
- Br: 2 (from \( 2 \, \text{NaBr} \))

6. **Final balanced equation:**
\[ 1 \, \text{Na}_2\text{O} + 1 \, \text{CaBr}_2 \rightarrow 2 \, \text{NaBr} + 1 \, \text{CaO} \]

This means the coefficients are 1:1:2:1.

Therefore, the correct answer is:
**c 1:1:2:1**.