Answer:
CH3CH2COOH< CLCH3CH2COOH<CLCH2COOH<CL2CHCOOH
Step-by-step explanation:
PKa is the negative logarithm of dissociation constant. It gives the relative strengths of the acids. Stronger acids have smaller pKa values and weak acids have larger pKa value.
The stronger the acid, the weaker its conjugate base. The larger the pKa of the conjugate base, the stronger the acid. The strength of an acid is inversely related to the strength of its conjugate.