Question

Which reaction leads to the formation of a precipitate?

2Cr(NO3)3(aq) + 3FeSO4(aq) →
2RbF(aq) + CuSO4(aq) →
2Ca(OH)2(aq) + 2FeCl3(aq) →

Answer 1

2Ca(OH)2(aq) + 2FeCl3(aq) on the dead locs

Answer 2

Answer:
`2Ca(OH)_2(aq)+2FeCl_3(aq)\rightarrow CaCl_2(aq)+2Fe(OH)_2(s)`

Explanation: A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

The reactions in which one of the product is formed as a solid are called as precipitation reactions.

a)
`2Cr(NO_3)_3(aq)+3FeSO_4(aq)\rightarrow Cr_2(SO_4)_3(aq)+3FeNO_3(aq)`

b)
`2RbF(aq)+CuSO_4(aq)\rightarrow Rb_2(SO_4)(aq)+CuF_2(aq)`

c)
`2Ca(OH)_2(aq)+2FeCl_3(aq)\rightarrow CaCl_2(aq)+2Fe(OH)_2(s)`