To determine the reactions for the given chemical combinations, we need to refer to the solubility rules and activity series of metals. The solubility rules help us identify which compounds are soluble in water and which will form precipitates. The activity series of metals helps us determine the reactivity and displacement reactions between metals.
a. Aqueous chromium(III) nitrate plus magnesium metal:
To determine if a reaction occurs, we need to check the activity series of metals. Magnesium is more reactive than chromium. Therefore, magnesium can displace chromium in a single displacement reaction. The balanced equation would be:
Mg (s) + Cr(NO3)3 (aq) → Mg(NO3)2 (aq) + Cr (s)
The magnesium reacts with the chromium(III) nitrate to form magnesium nitrate, and chromium is reduced to its elemental form.
b. Aqueous lithium sulfate plus aqueous barium chloride:
To determine if a reaction occurs, we need to consider the solubility rules. Lithium sulfate (Li2SO4) and barium chloride (BaCl2) are both soluble in water and therefore dissociate into ions. When we mix the solutions, a double displacement reaction occurs:
Li2SO4 (aq) + BaCl2 (aq) → 2 LiCl (aq) + BaSO4 (s)
The reaction forms lithium chloride and barium sulfate. Barium sulfate is insoluble and forms a precipitate.
c. Solid lead metal plus aqueous potassium chloride:
To determine if a reaction occurs, we need to check the activity series of metals. Lead is less reactive than potassium. Therefore, no reaction will occur between solid lead and aqueous potassium chloride. The balanced equation remains:
Pb (s) + 2 KCl (aq) → No reaction.
d. Aqueous lithium fluoride with aqueous ammonium phosphate:
To determine if a reaction occurs, we need to check the solubility rules. Both lithium fluoride (LiF) and ammonium phosphate [(NH4)3PO4] are soluble. When we mix the solutions, no reaction occurs, as all ions remain in solution. The balanced equation remains:
LiF (aq) + (NH4)3PO4 (aq) → No reaction.
In chemistry, it is important to refer to the solubility rules and activity series of metals to predict whether reactions will occur and to determine the products formed.