will a double displasment happen

[Emily Violet]

Hi my name is Sarah i'm in grade 11. 

I'm doing this assignment where you have to predict in a double displacement reaction is possible but i don't know how to tell. is there a kind of formula? is it to do if a solid becomes aqueous or vice versa. i asked my teacher but she was no help. Told me i should know this by now. 😔  

 

 

here are some of my example questions. 

a) Cu(NO3)2 and Zn(NO3)2

b) AlCl3 and AlBr3

c) Cr2(SO4)3 and FeCl3

d) Ba(NO3)2 and AgCH3COO

[StringJunky]

Try this Khan Academy lesson: https://www.khanacademy.org/science/chemistry/chemical-reactions-stoichiome/types-of-chemical-reactions/a/double-replacement-reactions