Which statement about Delta. Hf is true? It is zero for any compound in its standard state. It is positive when the bonds of the product store more energy than those of the reactants. It is negative when a compound forms from elements in their standard states. It is zero for any element that is in the liquid state.

Which of these statements are true? Select all that apply.

The TriHrxn for the reaction C(s) + O2(g) → CO2(g) is the same as the Tri Hf for CO2(g).

The Tri Hrxn for the reaction Na(s) + Cl2(g) → 2NaCl(s) is the same as the TriHf for NaCl(s).

The TriHf for Br2(l) is 0 kJ/mol by definition.

To determine the TriHf for H2O(g), just reverse the sign of the TriHrxn for the reaction 2H2O(l) → 2H2(g) + O2(g).