Nitrogen dioxide (NO2) does not have a high melting point. In fact, it has a relatively low melting point of -9.3 °C (15.3 °F; 263.8 K). This means that at temperatures below -9.3 °C, NO2 will exist as a solid.
When NO2 is heated, it undergoes a phase change from a solid to a gas without passing through a liquid phase. This process is known as sublimation. The boiling point of NO2 is 21.15 °C (70.07 °F; 294.30 K), which means that at temperatures above this point, NO2 will exist as a gas.
NO2 is a highly reactive and toxic gas. It is a reddish-brown gas with a pungent odor. Due to its reactivity, it is not commonly found in its pure form in nature. Instead, it is often produced as a byproduct of combustion processes, such as in car engines or power plants.
In terms of solubility, NO2 hydrolyses in water, meaning it reacts with water to form nitric acid. Therefore, it is not highly soluble in water. However, it is soluble in other organic solvents such as carbon tetrachloride (CCl4) and chloroform.
NO2 does not have a high melting point, but rather a relatively low melting point of -9.3 °C. Its boiling point is 21.15 °C, and it is soluble in certain organic solvents.