Question

A scientist measures the standard enthalpy change for the following reaction to be 4.6 kJ :
Fe(s) + 2 HCl(aq)---> FeCl2(s) + H2(g)
Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of HCl(aq) is ___ kJ/mol.

A scientist measures the standard enthalpy change for the following reaction to be -761.0 kJ :
2NO(g) + 2 H2---> (g)N2(g) + 2 H2O(l)
Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of NO(g) is __ kJ/mol.