The Van't Hoff factor for 0.1 M La (NO3)3 solution is found to be 2.74 the percentage dissociation of the salt is :

To find the percentage dissociation of the salt, we need to use the Van't Hoff factor and the concentration of the solution.

The Van't Hoff factor (i) represents the number of particles into which a compound dissociates in a solution. In this case, the Van't Hoff factor is given as 2.74.

The concentration of the solution is given as 0.1 M (moles per liter).

To calculate the percentage dissociation, we need to compare the number of moles of the dissociated ions to the total number of moles of the salt.

Since La(NO3)3 dissociates into La3+ and 3 NO3- ions, the total number of moles of the salt is equal to the concentration (0.1 M).

The number of moles of the dissociated ions can be calculated by multiplying the concentration by the Van't Hoff factor (i.e., 0.1 M * 2.74).

Therefore, the number of moles of the dissociated ions is 0.274 moles.

To find the percentage dissociation, we divide the number of moles of the dissociated ions by the total number of moles of the salt and multiply by 100.

Percentage dissociation = (0.274 moles / 0.1 moles) * 100 = 274%

Therefore, the percentage dissociation of the La(NO3)3 salt in the 0.1 M solution is 274%.