Question

The following pairs of soluble solutions can be mixed. In some cases, this leads to the formation of an insoluble precipitate. Decide, in each case, whether or not an insoluble precipitate is formed.

a. AlCl3 and K3PO4
b. RbCO3 and NaCl
c. Na2CO3 and MnCl2
d. K2S and NH4Cl
e. CaCl2 and (NH4)2CO3

Answer 1

Using solubility rules, AlCl3 and K3PO4 will form a precipitate (AlPO4), Na2CO3 and MnCl2 will form a precipitate (MnCO3), CaCl2 and (NH4)2CO3 will form a precipitate (CaCO3), but RbCO3 and NaCl, and K2S and NH4Cl will not form any precipitates.

Step-by-step explanation:

The question requires the use of solubility rules to predict whether mixing two aqueous solutions will result in a precipitation reaction, resulting in an insoluble compound.

1. For the mixture of AlCl3 and K3PO4, the possible products are AlPO4 (which is insoluble) and KCl (which is soluble), meaning a precipitate of AlPO4 will form.

2. The mixture of RbCO3 and NaCl will not yield any precipitate as all possible products are soluble according to solubility rules.

3. When Na2CO3 is mixed with MnCl2, the potential product MnCO3 is insoluble, resulting in a precipitate.

4. Combining K2S with NH4Cl does not lead to precipitation because all resultant compounds, including NH4 and K salts, are soluble.

5. Mixing CaCl2 with (NH4)2CO3 forms CaCO3, which is insoluble, hence a precipitate will form.

Answer 2

See explanation

Step-by-step explanation:

Let us see what happens when each solution is mixed;

a) AlCl3(aq) + K3PO4(aq) ------> 3KCl(aq) + AlPO4(s)

A precipitate is formed here

b) RbCO3(aq) + NaCl(aq) -------> This is an impossible reaction hence no solid precipitate is formed here

c) MnCl2(aq) + Na2CO3(aq) → 2NaCl(aq) + MnCO3(s)

A precipitate is formed.

d) K2S(aq) + 2NH4Cl(aq) ------> 2KCl(aq) + (NH4)2S(aq)

No solid precipitate is formed

e) CaCl2(aq) + (NH4)2CO3(aq) → CaCO3(s) + 2NH4Cl(aq)

A solid precipitate is formed