The depression in freezing point of water observed for the same amount of acetic acid, dichloro-acetic acid and trichloro acetic acid increases in the order given above. Explain briefly.

Explanation

Given acids are `CH_(3)COOH,CHCl_(2)COOH, C Cl_(3)COOH`.
The depression in freezing point of a solute in water depends upon the number of ions (or) particles in aqueous solution.
The given three acdis are arranged in the order of their acidic strengths (increasing order)
`CH_(3)COOH lt CHCl_(2)COOH lt C Cl_(3)COOH`
Due to the presence of three chlorine atoms `C Cl_(3)COOH` is more acidic than `CHCl_(2)COOH` and followed by `CH_(3)COOH`.
`:.` The order of depression in freezing point is
`CH_(3)COOH lt CHCl_(2)COOH lt C Cl_(3)COOH`