Precipitation reactions

Classify: What type of reaction is the golden rain reaction?

• Composition

• Decomposition

• Single displacement

• Double displacement

Identify: What are the yellow crystals seen in the first two videos?

• Lead nitrate

• Potassium iodide

• Lead iodide

• Potassium nitrate

In the diagram, the two reactants in the golden rain reaction are shown in the two beakers and the two products are shown in the conical flask, after settling of the solid. Drag the labels to identify the four chemicals.

a

d

c

b

potassium nitrate sol'n

potassium iodide sol'n

lead nitrate sol'n

lead nitrate

Answer explanation

Identify: What is the precipitate in this reaction?

(Hint the precipitate is a solid)

AgNO3 (aq) + NaCl (aq) → AgCl (s) + NaNO3 (aq)

• AgNO₃

• NaNO₃

• AgCl

• NaCl

• I'm not sure

Select: What symbol is used to show the state of a precipitate?

• (g)

• (l)

• (s)

• (aq)

• I'm not sure

Which of these compounds are soluble?

• Lead nitrate, Pb(NO₃)₂

• Mercury chloride, HgCl₂

• Magnesium sulfate, MgSO₄

• Potassium hydroxide, KOH

• I'm not sure

Which of these compounds are insoluble (i.e., form a precipitate)?

• Magnesium hydroxide, Mg(OH)₂

• Copper nitrate, Cu(NO₃)₂

• Zinc sulfate, ZnSO₄

• Silver bromide, AgBr

• I'm not sure