The calculated value might be -281.86 kcal/mol or 1179.3 J/mol. See Ref: J. Chem. Educ., 1965, 42 (9), 474
The standard heat/enthalpy of formation of SO2 is -296.8 KJ
The heat for this reaction is called the heat of solution for ammonium nitrate. When the reaction is finished, the system contains two substances, the calorimeter itself and the aqueous solution, and there is a heat associated with each component.
[from wikipedia] The standard enthalpy of formation"standard heat of formation" of a compound is the change of enthalpy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 bar of pressure and the specified temperature, usually 298.15 K or 25 degrees Celsius). Its symbol is ΔHfO.
The dissolution of ammonium chloride, like ammonium nitrate, is an endothermic process, meaning that it will absorb heat. The amount of heat absorbed per mole of ammonium chloride (53.49 g) is 14.7 kJ, enough to lower the temperature of one kilogram of water by 3.5 K.
-45.06 kJ/mol from Silberberg: Principles of General Chemistry Appendix B
The standard heat/enthalpy of formation of SO2 is -296.8 KJ
standred
The standard enthalpy of formation for potassium hydroxide is -425,8 kJ/mol.
-392.4 KJ/mol
standard heat of formation in a compound.
- Gibbs energy- Standard enthalpy of formation- Specific heat capacity
Standard Heat (Enthalpy) of Formation, Hfo, of any compound is the enthalpy change of the reaction by which it is formed from its elements, reactants and products all being in a given standard state.By definition, the standard enthalpy (heat) of formation of an element in its standard state is zero, Hfo = 0.Standard Molar Enthalpy (Heat) of Formation, Hmo, of a compound is the enthalpy change that occurs when one mole of the compound in its standard state is formed from its elements in their standard states.Standard Enthalpy (Heat) of Reaction, Ho, is the difference between the standard enthalpies (heats) of formation of the products and the reactants.Ho(reaction) = the sum of the enthalpy (heat) of formation of products - the sum of the enthalpy (heat) of formation of reactants: Ho(reaction) = Hof(products) - Hof(reactants)To calculate an Enthalpy (Heat) of Reaction:Write the balanced chemical equation for the reaction Remember to include the state (solid, liquid, gas, or aqueous) for each reactant and product.Write the general equation for calculating the enthalpy (heat) of reaction: Ho(reaction) = Hof(products) - Hof(reactants)Substitute the values for the enthalpy (heat) of formation of each product and reactant into the equation. Remember, if there are 2 moles of a reactant or product, you will need to multiply the enthalpy term by 2, if molar enthalpies (heats) of formation are used.Standard Enthalpy (Heat) of FormationExample: Standard Enthalpy (Heat) of Formation of WaterThe standard enthalpy (heat) of formation for liquid water at 298K (25o) is -286 kJ mol-1. This means that 286 kJ of energy is released when liquid water, H2O(l), is produced from its elements, hydrogen and oxygen, in their standard states, ie, H2(g) and O2(g).This reaction is written as:H2(g) + ½O2(g) -----> H2O(l) Hfo = -286 kJ mol-1The standard enthalpy (heat) of formation of water vapour at 298K (25o) is -242 kJ mol-1.This means that 242 kJ of energy is released when gaseous water (water vapour), H2O(g), is produced from its elements, hydrogen and oxygen, in their standard states, ie, H2(g) and O2(g).This reaction is written as:H2(g) + ½O2(g) -----> H2O(g) Hfo = -242 kJ mol-1
heat is one of the reactants.
3
Gently heat - ammonium chloride will sublime on a cold solid surface
It is not mandatory to heat this solution.
The standard enthalpy of formation for sodium chloride is -411,12 kJ/mol.