ΔH is path-independent — going around a closed cycle by either route gives the same answer. The anticlockwise (direct) and clockwise (via anchor) paths from R to P must be equal.

If you traverse an arrow against its direction, flip the sign of ΔH. Use the ⇄ button to redirect an arrow if its natural direction doesn't match what you want.

Formation → elements. Combustion → CO₂ + H₂O. Bond energy → gaseous atoms. Born-Haber → ladder between elements and ionic solid.

If your cycle has 2H₂O on one side, multiply ΔHf[H₂O] by 2. Always match coefficients in the target equation.