Final answer:
The smaller the pKa value, the stronger the acid. The strength of an acid can be influenced by factors such as the size of the atom carrying the acidic proton and the electronegativity of the atom within the same row of the periodic table. Stronger acids have weaker conjugate bases.
Step-by-step explanation:
The acid strength of a compound can be quantitatively measured using pKa, where the smaller the pKa value, the stronger the acid. For example, acetic acid (CH3COOH, pKa=4.76) is a stronger acid than ethanol (CH3CH2OH, pKa=15.9). The pKa value can be affected by factors such as the size of the atom carrying the acidic proton and the electronegativity of the atom within the same row of the periodic table.
Additionally, the relative strength of an acid is inversely related to the strength of its conjugate base, i.e., the stronger the acid, the weaker the conjugate base.
It's important to note that pKa values are logarithmic, meaning that smaller values indicate stronger acids.