When aqueous sodium hydroxide is added to zinc chloride, the reaction that takes place is:
ZnCl2 + 2Na(OH) --> 2NaCl + Zn(OH)2 (s)
Sodium chloride is soluble in water while Zn(OH)2 is precipitated as a white powder
When aqueous barium nitrate is added to aqueous zinc chloride there is no chemical reaction as the two chemicals do not react to form an insoluble precipitate which is one of the criteria for a double replacement reaction to take place. There is no formation of a white precipitate in this case.
When aqueous silver nitrate is reacted with zinc chloride the reaction that takes place is:
ZnCl2 + 2AgNO2 --> Zn(NO3)3 + 2AgCl
Silver chloride is precipitated as a white solid.