Question

Pure sodium oxide can be prepared by heating (1) \(\mathrm{NaNO}_{3}\) with \(\mathrm{Na}\) (2) \(\mathrm{NaNO}_{2}\) with \(\mathrm{Na}\) (3) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) with \(\mathrm{Na}\) (4) Both 1 and 2

Short answer

Both reactions (1) and (2) are valid for preparing pure sodium oxide.

Step-by-step solution

- Analyzing Sodium Nitrate Reaction

Consider the reaction of \( \mathrm{NaNO}_{3} \) with \( \mathrm{Na} \). \( \mathrm{NaNO}_{3} + 3 \mathrm{Na} \rightarrow \mathrm{Na}_2\mathrm{O} + N_2 \) and byproducts.

- Analyzing Sodium Nitrite Reaction

Consider the reaction of \( \mathrm{NaNO}_{2} \) with \( \mathrm{Na} \). \( \mathrm{NaNO}_{2} + 3 \mathrm{Na} \rightarrow \mathrm{Na}_2\mathrm{O} + N_2 \) and byproducts.

- Analyzing Sodium Carbonate Reaction

Consider the reaction of \( \mathrm{Na}_{2} \mathrm{CO}_{3} \) with \( \mathrm{Na} \). This reaction doesn't produce pure sodium oxide reliably.

- Conclusion

Both reactions (1) and (2) are valid methods for preparing pure sodium oxide by heating with sodium metal.

Key concepts

sodium nitrate reaction

Sodium nitrate (\text{NaNO}_3\text{) is a chemical compound that reacts with sodium (\text{Na}\text{) to form sodium oxide (\text{Na}_2\text{O}\text{) and nitrogen gas (\text{N}_2\text{) as the primary products. The reaction is as follows: \[\text{NaNO}_3 + 3\text{Na} \rightarrow \text{Na}_2\text{O} + \text{N}_2\text{\]. This process occurs when heated, and it's a reliable method to obtain pure sodium oxide. Sodium nitrate acts as an oxidizing agent, meaning it helps in the oxidation of sodium. Sodium in turn reduces the nitrate ion. The byproducts are typically trace amounts of other nitrogen oxides, but primarily, nitrogen gas is released. Given the efficiency and purity of the product, this chemical reaction is a practical way to synthesize sodium oxide in laboratory settings.

sodium nitrite reaction

Sodium nitrite (\text{NaNO}_2\text{) also reacts with sodium (\text{Na}\text{) to yield sodium oxide (\text{Na}_2\text{O}\text{) and nitrogen gas (\text{N}_2\text{). The reaction is represented by: \[\text{NaNO}_2 + 3\text{Na} \rightarrow \text{Na}_2\text{O} + \text{N}_2\text{\]. Similar to the sodium nitrate reaction, this reaction is completed upon heating. In this case, sodium nitrite serves as an oxidizing agent, facilitating the reduction of sodium while itself being reduced to form nitrogen gas. The purity of sodium oxide obtained through this method is comparable to that from the sodium nitrate reaction. However, the choice between using \text{NaNO}_3\text{ or \text{NaNO}_2\text{ often depends on other practical considerations such as availability, cost, and the specific requirements of the synthesis process.

sodium carbonate reaction

Sodium carbonate (\text{Na}_2\text{CO}_3\text{) reacts with sodium (\text{Na}\text{) but does not reliably produce pure sodium oxide (\text{Na}_2\text{O}\text{). The attempted reaction is: \[\text{Na}_2\text{CO}_3 + 2\text{Na} \rightarrow 3\text{Na}_2\text{O} + \text{CO}_2\text{\]. However, this reaction is often complicated by the formation of carbon dioxide (\text{CO}_2) and potential side reactions that can lead to impurities. Thus, it is not considered effective for preparing pure sodium oxide. The presence of carbonates and incomplete reaction can result in a mixture rather than the desired pure product. Therefore, for synthesizing pure sodium oxide, other methods such as the reactions using \text{NaNO}_3\text{ or \text{NaNO}_2\text{ are preferred.