9.5Strengths of Ionic and Covalent Bonds
Section · module m71830
What this needs
Learn these first — this section will not make sense without them.
Nothing in the algebra book is a prerequisite for this section.
What this touches
Algebra that turns up here. Not a blocker, but this is where you will see it used.
ΔH = ΣDbonds broken − ΣDbonds formed subtracts one sum from another; treating it as an addition (or forgetting which group is being subtracted) flips exothermic and endothermic in the answer even when every individual bond energy was looked up correctly.
- Applies5.9Modeling Using Variation
Lattice energy ΔHlattice = C(Z⁺)(Z⁻)/Ro is a joint-variation relationship — directly proportional to the product of the ionic charges and inversely proportional to interionic distance — which is why doubling both charges while holding Ro fixed quadruples the lattice energy rather than doubling it.