Please, can you help me understand how the Vant Hoff process works?

Here some exemples:
K2CO3 --> 2K+ + 1 CO3-- ; i= 2+1 =3
CaCl2 ---> 1Ca+ + 2Cl- ; i = 1+2=3
HCl ------> 1H+ + 1Cl- ; i = 1+1=2
KBr-------->1K+ + 1Br- ; i = 1+1=2

Since the colligative properties depend upon the number of particles, we have to define vont hoff factor to account for association/dissociation of molecules. When molecules associate/dissociate, number of particles change and colligative properties change.

The general formula for ''i'' in association is, i = 1 + (n-1)α , where α is degree of dissociation. In case of strong electrolytes like the salts you posted, alpha is 1, thus i = n.

Approve if i helped :)

Always Remember that for Strong Electrolytes or Coumpounds Vant Hoff factor is equals to the no of ions.

Examples U have mention above like in:P

K2CO3 --> 2K+ + 1 CO3

i= 2+1 =3 
thus, it dissociates into ions in potassium and carbonate witheir coeff. 2 and 1 Therfore
Vant hoff factor will be equal to i = 2 + 1 = 3
which is the answer.

And also for non - electrolyte compounds vant hoff factor is alwas takes as 1 becoz they partially dissociates not inot ions.
For example - UREA ,GLUCOSE etc.

approve!