There isn't a single "formula" for lithium carbonate heat. Instead, you need to specify what you're looking for. Here are some possibilities and how to approach them:

1. Heat of Formation (Standard Enthalpy of Formation):

* This is the heat change when 1 mole of lithium carbonate (Li₂CO₃) is formed from its elements in their standard states (lithium metal, solid carbon, and oxygen gas) at 298 K and 1 atm.

* Symbol: ΔHf°

* Value: -1215.2 kJ/mol

* Formula: Li₂(s) + C(s) + 3/2 O₂(g) → Li₂CO₃(s) + ΔHf°

2. Heat of Decomposition (Standard Enthalpy of Decomposition):

* This is the heat change when 1 mole of lithium carbonate decomposes into its constituent oxides (lithium oxide and carbon dioxide) at standard conditions.

* Symbol: ΔHd°

* Value: You can calculate this from the heat of formation of lithium carbonate and the heat of formation of the products.

* Formula: Li₂CO₃(s) + ΔHd° → Li₂O(s) + CO₂(g)

3. Heat Capacity (Specific Heat Capacity):

* This measures the amount of heat required to raise the temperature of 1 gram of lithium carbonate by 1 degree Celsius.

* Symbol: Cp

* Value: 1.02 J/(g·K)

* Formula: Q = m × Cp × ΔT (where Q is heat, m is mass, and ΔT is temperature change)

4. Heat of Reaction:

* This is the heat change associated with a specific chemical reaction involving lithium carbonate.

* Formula: This will depend on the specific reaction, and you would need to use Hess's Law to calculate it using the heats of formation of the reactants and products.

Remember:

* The values provided for heat of formation and heat capacity are approximate and may vary slightly depending on the source.

* To calculate the heat involved in specific scenarios, you'll need to apply the relevant formulas and consider the specific reaction conditions (mass, temperature change, etc.).

Let me know if you have a specific scenario or calculation in mind, and I can help you further!