Lecture 0502

Types of Types of ReactionsReactions

Types of Reactions

1. Synthesis [composition]

elements compounds

Synthesis of Sodium Chloride

Types of Reactions

2. Decomposition

Compound elements and/or simpler cmpds

Decomposition of HgO

3. Single displacement

a more reactive element replaces a less reactive element in a compound

Types of Reactions

Sodium in Water

4. Double displacement (metathesis reaction) solutions of two ionic

compounds react to form a solid product

(precipitate), or a molecular substance

Types of Reactions

Double Displacement

Pb(NOPb(NO33) ) 22(aq) + 2 KI(aq)(aq) + 2 KI(aq)

PbIPbI22(s) + 2 KNO(s) + 2 KNO33 (aq) (aq)

The anions The anions exchange places exchange places between cations.between cations.

Lead (II) Iodide

AX + BY AY + BX

Solubility of Salts in Water

1. Most nitrate salts are soluble

2. Most salts containing the alkali metal ions and the ammonium ion are soluble

Solubility of Salts in Water

3. Most chloride, bromide, and iodide salts are

soluble, EXCEPT of salts containing the ions of

silver, lead (ll), and mercury (l)

Solubility of Salts in Water

4. Most sulfate salts are soluble, EXCEPT with ions of barium, lead (Il), mercury (ll), and calcium

Solubility of Salts in Water

5. Most hydroxide salts are only slightly soluble. The important soluble hydroxides are NaOH and KOH. Barium, strontium, and calcium hydroxides are marginally soluble

6. Most sulfide, carbonate, chromate, and phosphate

salts are only slightly soluble

Figure 5.1 in text

Pg 48 in TUCEH

Solubility of Salts in Water

Types of Reactions

5. Combustion of hydrocarbons

hydrocarbon + O2

CO2 + H2O

Molecular Equations

Gives overall reaction stoichiometry, but NOT necessarily the actual forms of reactants & products in solution.

Ionic Equations

Represents as ions all reactants and products

that are strong electrolytes.

NET Ionic Equations

Includes only those solution components undergoing change

Spectator ions are not included.

Net Ionic Equations

Mg (s) + 2 HCl (aq) H2 (g) + MgCl2 (aq)

We really should write…

Mg (s) + 2 H+ + 2 Cl- H2 (g) + Mg2+ + 2 Cl-

Net Ionic EquationsMg (s) + 2 H+ + 2 Cl- H2 (g) + Mg2+ + 2 Cl-

The two Cl- ions are SPECTATOR IONS

They do not participate. Could have used any X-

Practice Ch 6-10In TUCEH