Precipitation Reactions

Precipitation Reactions and Solubilty Rules

How to know when a solid will form

RECAP: What is a precipitation reaction

• A precipitation reaction refers to the formation of an insoluble ionic compound when two aqueous solutions are combined.

• The reason water dissolves some ionic compounds is the attraction between the water and the cations/anions is stronger than the attraction between the cations and anions

• Today we will learn the rules to identify if a solid will form when two aqueous solutions are mixed

Multiple Choice

The S in SNAPE stands for

• Silicon (Si⁴⁺)

• Sulfide (S^2-)

• Sulfate (SO₄^2-)

• Sodium (Na⁺)

Multiple Choice

The P in SNAPE stands for

• Phosphorus (P^3-)

• Potassium (K⁺)

• Phosphate (PO₄^3-)

• Lead (Pb²⁺)

Multiple Choice

TRUE or FALSE: Aluminum is one of the ions in SNAPE

• True

• False

Multiple Choice

What does the N in SNAPE stand for?

• Nitrogen (N³⁺)

• Sodium (Na⁺)

• Nitrate (NO₃^-)

• Neon (Ne)

Multiple Choice

TRUE or FALSE: Ethanoate is a polyatomic ion

• True

• False

RULE 2: Halides (Mostly Soluble)

Halides are chemical compounds that contain Halogens.

RULE 2: Halides (Mostly Soluble)

• Halides are chemical compounds that contain Halogens.

• Halogens are group 17 elements; Fluorine, Chlorine, Bromine and Iodine

• Halides are soluble in water EXCEPT

• When they contain Silver (Ag⁺) and Lead (Pb²⁺)

Rule 3: Sulfates (Mostly Soluble)

• Ionic compounds containing Sulfate are soluble with water EXCEPT

• When they contain Stronium, Barium or Lead

Multiple Choice

Sodium Chloride is a halide, it is _______ in water

• Soluble

• Insoluble

Multiple Choice

Lead Bromide is a halide, it is _______ in water

• Soluble

• Insoluble

Multiple Choice

Which of the following is soluble in water?

• Barium Sulfate

• Strontium Sulfate

• Silver Sulfate

• Lead Sulfate

Rule 4: Hydroxides (Usually Insoluble)

• Hydroxides are ionic compounds containing Hydroxide (OH^-). They are usually insoluble EXCEPT

• When the contain Sodium, Ammonium, Potassium and Barium

• *Notice that 3 of these are from SNAPE

Multiple Choice

Which of the following is insoluble in water?

• Ammonium Hydroxide

• Barium Hydroxide

• Potassium Hydroxide

• Zinc Hydroxide

Multiple Choice

Which of the following is soluble in water?

• Nickel Hydroxide

• Copper Hydroxide

• Sodium Hydroxide

• Zinc Hydroxide

Rule 5: Carbonates, Phosphates and Sulfides

• These three are all the same

• They are always insoluble EXCEPT

• When they are mixed with Sodium, Potassium and Ammonium

• *All three from SNAPE (so you don't need to remember)

Multiple Choice

Potassium Sufide is

• Soluble

• Insoluble

Multiple Choice

Zinc Carbonate is

• Soluble

• Insoluble

Multiple Choice

Magnesium Phosphate is

• Soluble

• Insoluble

And that is it

• You don't need to remember the solubility rules

• Because you will have a handy solubility table

• But the better you understand these rules, the better you will be at using the table