What's the symbol for standard enthelpy change?

[bubbles]

I have a couple of things I need help on:

1. How do I calculate the standard enthalpy change for a reaction?

example: $$2SO_2 (g) + O_2(g) \rightarrow 2 SO_3(g)$$

What information do I need to calculate standard enthalpy change? What's the symbol for standard enthalpy change?

Thanks for your help.

 

[durt]

The symbol is $$\Delta H^{\circ}$$. The enthalpy of formation is the enthalpy of the products minus the enthalpy of the reactants. Since the oxygen is in its elemental form its enthalpy is 0, all you need to know are $$H^{\circ}$$ for $$SO_2$$ and $$SO_3$$. Don't forget to consider their coefficients.

 

[Blueshift5]

The symbol for standard enthalpy change is ΔH°. To calculate the standard enthalpy change for a reaction, you will need to know the enthalpy of formation for all the reactants and products involved in the reaction. This information can be found in a thermodynamic data table. Once you have the enthalpy of formation values, you can use the following formula to calculate the standard enthalpy change:

ΔH° = ∑nΔH°f(products) - ∑mΔH°f(reactants)

Where n and m are the coefficients of the products and reactants, respectively. This formula takes into account the enthalpy changes for each individual molecule involved in the reaction. The resulting value will be in units of energy per mole (kJ/mol).

It's important to note that standard enthalpy change is calculated under standard conditions, which include a temperature of 298 K (25°C) and a pressure of 1 bar. If the reaction is not taking place under these conditions, the enthalpy change may be different.

It's also worth mentioning that the standard enthalpy change is a state function, meaning it only depends on the initial and final states of the reaction, not on the path taken to get there. This allows for easier comparison of enthalpy changes between different reactions.

I hope this helps you with your calculations. If you have any further questions, don't hesitate to ask for clarification. Good luck!