Synthesis database: Lithium nitrate synthesis

Lithium nitrate can be easily synthesized by reacting nitric acid with lithium carbonate, which is described by the following equation:

Li₂CO₃ + 2HNO₃ -> 2LiNO₃ + H₂O + CO₂

In this case, 14% nitric acid, and a sample of mainly lithium carbonate has been used. Although the mentioned sample was initially mainly composed of lithium hydroxide, it gradually reacted with the carbon dioxide in air, thereby forming lithium carbonate. Because of this property, the mentioned reaction, along with other similar reactions, is used in submarines and spacecraft for absorbing excess carbon dioxide from the air.

Along with the mentioned compounds, it was also necessary to prepare a scale, an Erlenmeyer flask, and some kind of pH indicator, the purpose of which was to determine the moment when all the acid has been neutralized. Although, in this case, a common universal pH indicator has been used, mainly for the purpose of confirming neutralization, which can also be easily noticed due to the sudden reduction in carbon dioxide generation.

Approximately 50 grams of nitric acid (w = 40%, n = 0.317 moles) have been added to an Erlenmeyer flask. After that, lithium carbonate has been gradually added. In total, 11.9 grams (0.161 moles) of lithium carbonate have been added to the nitric acid.

After the reaction, most of the water from the reaction solution has been boiled away by heating it for a certain period of time. Approximately 19.3 grams (0.278 moles) of lithium nitrate remained as a solid. Although lithium nitrate usually comes in form of colorless crystals, in this case the crystals were slightly yellow colored due to the impure reactants used for this reaction.