For the reaction:
Agl(s) + V2Br2(g) AgBr(s) + /12 ()
AH° = -54.0 kJ
And:
AH® for AgBr(s) = -100.4 kJ/mol
AH° for Br2(g) = +30.9 kJ/mol
Therefore value of AH for Agl(s) must be:
+61.8 kJ/mol.
-61.8 kJ/mol.
O-123.5 kJ/mol.
+77.3 kJ/mol.
O-77.3 kJ/mol.