Question

Double Replacement Reactions: Complete and balance. Identify the precipitate (highlight it!!)?

Answer 1

In aqueous solution we would expect ionization of the individual reagents.......

Explanation:

`(i)` `Ag^(+) + Cl^(-)rarrAgCl(s)darr`

`AgCl` is as soluble as a brick. The state is indicated by `(s)`, i.e. `"solid"`; some chemists put a down arrow as shown to emphasize its precipitation.

ELSE,

`2AgNO_3(aq) + MgCl_2(aq) rarr 2AgCl(s) darr +Mg(NO_3)_2(aq)`

The magnesium ions, and the nitrate ions are thus along for the ride and do not participate in MACROSCOPIC chemical change.

`(ii)` `Fe^(2+) + HO^(-)rarrFe(OH)_2(s)darr`

ELSE,

`FeCl_2(aq) + 2NaOH(aq) rarr Fe(OH)_2(s) darr +2NaCl(aq)`

The sodium ions, and the chloride ions are thus along for the ride and do not participate in MACROSCOPIC chemical change.

`(iii)` `CO_3(aq)^(2-) + Fe^(2+)rarrFeCO_3(s)darr`

ELSE,

`Na_2CO_3(s) + FeSO_4(aq) rarr 2FeCO_3(s) darr +Na_2(SO_4)(aq)`

Upon dissolution of the salts in an aqueous medium; SOME of the ions are spectator ions and thus do not participate in reaction. The given net ionic equations reflect the macroscopic chemical change.