On adding AgNO3 solution to KI solution, a negatively charged colloidal sol will be formed in which of the following conditions ?

To prepare Negative sol,  Excess of KI must be present      AgNO3               KI(1) 0.01moles         0.01moles  (2) 0.01moles         0.01moles  (3) 0.02moles         0.01moles   (4) 0.01moles         0.015moles           4th   option is correct