Answer:
A) NiBr₂ and AgNO₃
Explanation:
We can use the solubility rules to decide which reaction gives the precipitate.
The important ones for this problem are:
- Salts of Group I elements and of ammonia are soluble.
- Nitrates are soluble.
- Halides are soluble. Important exceptions the silver halides.
- Most sulfates are soluble.
- Most hydroxides are slightly soluble.
The possible products from each reaction are
A) Ni(NO₃)₂ and AgBr; B) NaBr and KI; C) KCl and Cr₂(SO₄)₃
D) KNO₃ and Ba(OH)₂; E) LiI and Cs₂CO₃.
A) Ni(NO₃)₂ and AgBr
Ni(NO₃)₂ — soluble (Rule 2)
AgBr — insoluble (an exception to Rule 3)
When aqueous solutions of NiBr₂ and AgNO₃ are mixed, a precipitate forms.
B) NaBr and KI
NaBr — soluble (Rule 1)
KI — soluble (Rule 1)
C) KCl and Cr₂(SO₄)₃
KCl — soluble (Rule 1)
Cr₂(SO₄)₃ — soluble (Rule 4)
D) KNO₃ and Ba(OH)₂
KNO₃ — soluble (Rule 1)
Ba(OH)₂ — soluble (Rule 5)
E) LiI and Cs₂CO₃
LiI — soluble (Rule 1)
Cs₂CO₃ — soluble (Rule 1)
