To balance the chemical equation \( \text{Na}_2\text{O} + \text{CaBr}_2 \rightarrow \text{NaBr} + \text{CaO} \), we will assign coefficients to each compound and balance the equation step by step.
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Start with the unbalanced equation: \[ \text{Na}_2\text{O} + \text{CaBr}_2 \rightarrow \text{NaBr} + \text{CaO} \]
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Count the number of atoms of each element on both sides:
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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 \(\text{CaBr}_2\))
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Right side:
- Na: 1 (from \(\text{NaBr}\))
- O: 1 (from \(\text{CaO}\))
- Ca: 1 (from \(\text{CaO}\))
- Br: 1 (from \(\text{NaBr}\))
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To balance sodium (Na), we place a coefficient of 2 before NaBr: \[ \text{Na}_2\text{O} + \text{CaBr}_2 \rightarrow 2 \text{NaBr} + \text{CaO} \]
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Now, count again:
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Left side:
- Na: 2
- O: 1
- Ca: 1
- Br: 2
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Right side:
- Na: 2 (from \(2\text{NaBr}\))
- O: 1 (from \(\text{CaO}\))
- Ca: 1
- Br: 2 (from \(2\text{NaBr}\))
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All the elements are now balanced: \[ \text{Na}_2\text{O} + \text{CaBr}_2 \rightarrow 2 \text{NaBr} + \text{CaO} \]
Thus, the coefficients are:
- Na2O: 1
- CaBr2: 1
- NaBr: 2
- CaO: 1
The balanced equation is:
1:1:2:1
So the correct answer is: 1:1:2:1.