Potassium iodide reacts with lead(II) nitrate in the following precipitation reaction:
2KI(aq)+Pb(NO3)2(aq)→2KNO3(aq)+PbI2(s)

What minimum volume of 0.200 M potassium iodide solution is required to completely precipitate all of the lead in 155.0 mL of a 0.122 M lead(II) nitrate solution?

Respuesta :

Answer:

0.1891 L minimum volume of 0.200 M potassium iodide solution is required.

Explanation:

Considering:

[tex]Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}[/tex]

Or,

[tex]Moles =Molarity \times {Volume\ of\ the\ solution}[/tex]

Given :

For lead(II) nitrate solution :

Molarity = 0.122 M

Volume = 155.0 mL

The conversion of mL to L is shown below:

1 mL = 10⁻³ L

Thus, volume = 155.0×10⁻³ L

Thus, moles of lead(II) nitrate :

[tex]Moles=0.122 \times {155.0\times 10^{-3}}\ moles[/tex]

Moles of lead(II) nitrate  = 0.01891 moles

According to the given reaction:

[tex]2KI_{(aq)}+Pb(NO_3)_2_{(aq)}\rightarrow 2KNO_3_{(aq)}+2PbI_2_{(aq)}[/tex]

1 mole of lead(II) nitrate reacts with 2 moles of potassium iodide

0.01891 mole of lead(II) nitrate reacts with 2*0.01891 moles of potassium iodide

Moles of potassium iodide = 0.03782 moles

Also,

Molarity = 0.200 M

Volume = ?

[tex]Volume=\frac{Moles\ of\ solute}{Molarity}[/tex]

[tex]Volume=\frac{0.03782}{0.200}\ L=0.1891\ L[/tex]

0.1891 L minimum volume of 0.200 M potassium iodide solution is required.