When sodium burns in oxygen, it produces sodium oxide (Na2O) and sodium peroxide (Na2O2). This reaction is highly exothermic, releasing a significant amount of heat and light. The chemical equation for the reaction can be represented as:

[ 4Na + O_2 rightarrow 2Na_2O ]

[ 2Na + O_2 rightarrow Na_2O_2 ]

The formation of sodium peroxide is more common at higher temperatures, while sodium oxide is the primary product at lower temperatures. The reaction is facilitated by the high reactivity of sodium, which readily loses its outermost electron to form a sodium cation (Na+). The oxygen molecules (O2) then accept these electrons to form oxide ions (O2-), leading to the formation of sodium oxide and sodium peroxide.

The heat generated during the reaction can reach temperatures of up to 2,700 degrees Celsius, which is sufficient to melt the sodium metal. This intense heat can also cause the sodium peroxide to decompose into sodium oxide and oxygen gas (O2) under certain conditions:

[ 2Na_2O_2 rightarrow 2Na_2O + O_2 ]

The production of sodium peroxide is significant due to its various applications, including as an oxidizing agent in rocket propellants and as a bleaching agent in the paper industry. The reactivity of sodium with oxygen also poses a significant safety risk, as the reaction can be spontaneous and explosive.

The data supporting these findings come from various sources, including experimental studies and theoretical calculations. For instance, research conducted by the National Institute of Standards and Technology (NIST) provides detailed information on the thermodynamics of the sodium-oxygen system. According to NIST, the standard enthalpy of formation for sodium oxide is -411.2 kJ/mol, while that for sodium peroxide is -424.2 kJ/mol. These values indicate the energy released during the formation of these compounds, which is a clear indication of the exothermic nature of the reaction.

In addition, studies by the U.S. Department of Energy have shown that the reaction between sodium and oxygen can produce temperatures of up to 2,700 degrees Celsius, which is consistent with the observations of the intense heat and light produced during the reaction. These findings underscore the importance of understanding the sodium-oxygen reaction for both scientific research and practical applications.