How many of the following may cause coagulation in colloidal solutions?
(a) Tanning
(b) Dialysis
(c ) Cataphoresis
(d) Mixing of a lyophilic sol with a lyophobic sol
(e) Mixing of two lyophobic sols
(f) Mixing sol-I (`AgNO_(3)` with excess KI) and sol-II (KI with excess `AgNO_(3)`)
(g) Addition of alcohol to a hydrophilic sol followed by addition of small quantity of electrolyte
(h) Centrifuging
(i) Freezing
