Determine the value of the enthalpy change, AH an, for the following reaction using the information below.

Question

AP Chemistr
4 Al ( * 3 MOz) → 2 Al,03 (s) + 3 Min (s)
2 Al+ 3/2 02(→ AL,O36)
ДН = -1676 kJ
ДН = -520.0 kJ

Answer 1

To determine the enthalpy change for the given reaction, we can use the following equation:

AH = ΣnAHf(products) - ΣnAHf(reactants)

Given:
AHf of Al2O3 = -1676 kJ
AHf of Al = 0 kJ (since Al is in its standard state)
AHf of O2 = 0 kJ (since O2 is in its standard state)

Since the AH for Al2O3 and Al are already given, we can calculate the AH for the reaction involving 2 Al and 3/2 O2 to get the AH for the overall reaction.

AH = (2 * -1676 kJ) - [2 * 0 kJ + (3/2) * 0 kJ]
AH = -3352 kJ

Therefore, the enthalpy change for the given reaction is -3352 kJ.