When aqueous solutions of are mixed, a precipitate forms. select one:
a. k2so4 and crcl3
b. nai and kbr
c. li2co3 and csi
d. koh and ba(no3)2 incorrect
e. nibr2 and agno3?

I believe the correct answer would be E. When aqueous solutions of NiBr 2 and AgNO3 are mixed, a precipitate forms. As these two solutions are being mixed a reaction would happen resulting to two new compounds which are nickel nitrate and silver bromide. The reaction would be:

NiBr2 + AgNO3 = NiNO3 + AgBr2 

The precipitate that would be formed would be the silver bromide since most of the silver compound are not or has low solubility in water while most of the nitrate compounds are very soluble in water. Most likely, it would be the silver bromide that is the precipitate.