Question

Use the unbalanced chemical equation to answer the question.

2NaHCO3 −> Na2CO3 + CO2
2
𝑁
𝑎
𝐻
𝐶
𝑂
3

−
>

𝑁
𝑎
2
𝐶
𝑂
3

+

𝐶
𝑂
2

Which of the following can be added to the products to balance the equation?

(1 point)
Responses

O2
𝑂
2
cap o sub 2

H2O
𝐻
2
𝑂
cap h sub 2 cap o

CH2OH
𝐶
𝐻
2
𝑂
𝐻
cap c cap h sub 2 cap o cap h

H2

Answer 1

To balance the given unbalanced chemical equation:

\[
2 \text{NaHCO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{CO}_2
\]

we start by analyzing the reactants and products:

1. On the left side, we have:
- 2 Sodium (Na)
- 2 Carbon (C) (1 from Na2CO3 and 1 from CO2)
- 6 Oxygen (O) (3 for each NaHCO3, total of 6)
- 2 Hydrogen (H)

2. On the right side, after decomposition, we have:
- 2 Sodium (Na) from Na2CO3
- 2 Carbon (1 from Na2CO3 and 1 from CO2)
- 3 Oxygen from Na2CO3 (3) and 2 Oxygen from CO2 (2), total of 5
- No Hydrogen (H)

To balance this equation while considering the products already formed (Na2CO3 and CO2), we would need to look for H-containing compounds or O2 to balance out the hydrogen.

From the answer options provided:

- **O2** can be added to balance the number of O atoms, but it doesn’t address the hydrogen imbalance.
- **H2O** would add oxygen and hydrogen, which could help balance the equation, but we already reach a point where hydrogen is created in the reaction, creating an imbalance with respect to initial sodium bicarbonate.
- **CH2OH** brings additional carbon, hydrogen, and oxygen, which can disrupt the balance.
- **H2** would add hydrogen without addressing the oxygen issues.

Since H2O adds both oxygen and balances potential hydrogen issues, it's the option that helps us to work towards an overall balanced equation effectively, although we would still need to adjust for the number of carbons and oxygens after additions.

In conclusion, **H2O** can be added to the products to help balance the equation, making it a valid answer option.