Question

difference between acidic strength order and acidity order

Answer 1

Answer:

Acid strength:

1. Acid strength refers to the tendency of an acid, symbolised by the chemical formula HA, to dissociate into a proton, H⁺, and an anion, A⁻.
2. The dissociation of a strong acid in solution is effectively complete, except in its most concentrated solutions.

Acid order:

1. The relationship between conjugate basicity and acidity is an inverse one, so the order of acidity is: CH4 (weakest acid) < NH3 < H2O < HF (strongest acid).
2. The actual pKa values agree with this prediction: CH4 pKa 51 (weakest acid), NH3 pKa 38, H2O pKa 15.7 and HF pKa 3.2.

Answer 2

Answer:

☑ The bond strength of an acid generally depends on the size of the 'A' atom: the smaller the 'A' atom, the stronger the H-A bond. When going down a row in the Periodic Table (see figure below), the atoms get larger so the strength of the bonds get weaker, which means the acids get stronger.