The thermite reaction used ofr welding of metals involves the reaction
`2Al(s) + Fe_(2)O_(3)(s) rarr Al_(2)O_(3)(s) + 2Fe(s)`
What is `Delta H^(@) ` at `25^(@)C` for this reaction ? Given that the standard heats of formation of `Al_(2)O_(3)` and `Fe_(2)O_(3)` are - 1675.7 kJ and - 828.4 kJ `mol^(-1)` respectively.

Explanation

To calculate the standard enthalpy change (ΔH°) for the thermite reaction given by:

\[ 2Al(s) + Fe_2O_3(s) \rightarrow Al_2O_3(s) + 2Fe(s) \]

we can use the standard heats of formation (ΔH_f°) for the reactants and products involved in the reaction.

### Step-by-Step Solution:

...