Warmup

2NaBr(aq) + Pb(OH)2(aq) PbBr2(s) + 2NaOH(aq)

1. Write (predict products too) and balance this equation: sodium bromide and lead(II)hydroxide solutions are mixed to create a precipitate in a basic solution.

You’ll need your solubility rules, ion sheets, and Oops I Did it Again Lab today.

Net Ionic Equations

2Na++ 2Br-+ Pb2+ + 2OH- Pb2+ + 2Br- + 2Na+ + 2OH-

2Br-(aq) + Pb2+(aq) PbBr2(s)

Actually….in double replacement reactions, we only show the species that changed phase, or that were integrated or disintegrated into something new. We

eliminate “spectator ions” and just show the net ionic equation. Also, we have to use solubility rules to

predict the precipitate.

Part I: Net Ion Equations

For each pair of ionic compounds shown:

a. Split the reactants into ions and write the complete ionic equation.

b. Write the net ionic equation. Indicate solid precipitates (insoluble compounds) in the products.

Na2S(aq) + AlCl3(aq) ???????????

Na+ + S2- + Al3+ + Cl- Na+ + S2- + Al3+ + Cl-

3S2-(aq) + 2Al3+(aq) Al2S3(s)

Ba(NO3)2(aq) + Ag2SO4(aq) ???????????

Ba2+ + NO3- +Ag+ + SO4

2- Ba2+ + NO3- + Ag+ + SO4

2-

Ba2+(aq) + SO42- (aq) BaSO4(s)

Hint: chlorates tend to be soluble

For each pair of ionic compounds shown:

a. Split the reactants into ions and write the complete ionic equation.

b. Write the net ionic equation. Indicate solid precipitates (insoluble compounds) in the products.

Pb3(PO4)2(aq) + NaClO3(aq)

Pb2+ +PO43- + Na+ + ClO3

- Pb2++ PO43- +Na+ + ClO3

-

NO REACTION

KI(aq) + Pb(NO3)2(aq)

K+ + I- + Pb2+ + NO3- K+ + I- + Pb2+ + NO3

-

2I-(aq) + Pb2+(aq) PbI2(s)

A potassium chromate solution and barium nitrate solution are combined, producing a yellow precipitate. Write the net ionic equation for this reaction and identify the precipitate.

K2CrO4(aq) + Ba(NO3)2 (aq) productmolecular equation

2K+ +CrO42- +Ba2+ + 2NO3

- 2K+ +CrO42- +Ba2+ +2NO3

-

complete ionic equation

2KNO3(?) and BaCrO4(?)

CrO42-(aq) + Ba2+(aq) BaCrO4(s)

(do these with a neighbor, 5 minutes)

Write the net ionic equation for the reaction, if any, that occurs when aqueous solutions of the following are mixed. You will have to predict and write the products!

a. Chromium(III) chloride and sodium hydroxide

b. Silver nitrate and ammonium carbonate

c. Copper(II)sulfate and mercury(I) nitrate

d. Strontium nitrate and potassium iodide

a. Chromium(III) chloride and sodium hydroxide

Cr3+(aq) + 3OH-(aq) Cr(OH)3(s)

b. Silver nitrate and ammonium carbonate

Ag+(aq) + CO32-(aq) Ag2CO3(s)

c. Copper(II)sulfate and mercury(I) nitrate

SO42-(aq) + Hg2

2+(aq) Hg2SO4(s)

d. Strontium nitrate and potassium iodide

Sr2+ + NO3- + K+ + I- Sr2+ + NO3

- + K+ + I-

NO REACTION

Oooops I Did it Again! Lab!

• Spend 10 minutes on prelab

• Please label all 8 of your disposable pipets and do NOT throw them away!