<u>Answer:</u> Van't Hoff factor, i is <u>less</u> than expected from the formula of the compound and this <u>decreases</u> the effective concentration of particles.
<u>Explanation:</u>
Strong electrolytes are defined as the solutions which completely dissociate into their ions.
But, most of the strong electrolytes do not dissociate completely (act ideally) but remain partially undissociated into the ions. Thus, giving a lesser number of ions in the solution than expected.
This means that the Van't Hoff factor, <em>i</em> which denotes the number of ions is <u>less</u> than expected.
As fewer ions are released in the solution, the concentration of the solution is expected to <u>decrease</u>.
Hence, van't Hoff factor, i is <u>less</u> than expected from the formula of the compound and this <u>decreases</u> the effective concentration of particles.