chapter4

** 4.1 General Properties of Aqueous Solutions **  // What is a solution? // A **solution** is a //homogeneous mixture// of //substances//. If there is much more of one substance than any others, then that substance is referred to as the **solvent**, all other substances in the mixture are called **solutes**.
 * Chapter 4 Reactions in Aqueous Solutions **

An **aqueous solution** is one whose solvent is water. Many properties of an aqueous solution are //similar// to the properties of water 1 (//e.g.// density, viscosity, melting point, boiling point). Most properties will be slightly changed by the presence of solutes, and some //may// be changed drastically, such as color and electrical conductivity.

The properties of the //solutes// are greatly changed and we define the **aqueous state** as distinct from the solid, liquid and gaseous states of matter. The solute molecules no longer interact with each other 2 , as they are spread out in the solution. The solutes are //solvated// by water molecules. That is, they are surrounded by solvent molecules, usually with some degree of order, imposed by the polarity of the water molecules and the polarity or charge of the solute.

Some solutes remain molecular (//e.g.// sugar, ethanol). In order to be soluble in water they must be somewhat polar molecules 3 . These solutes have no effect on the electrical properties of the solution and are classified as **non-electrolytes**. Some solutes are dissociated into ions when they dissolve in water, (//e.g//. NaCl, HBr). These solutes increase the electrical conductivity of water and are classified as highly mobile and electrically charged aqueous ions.
 * Electrolytes**
 * electrolytes**. Ions increase the conductivity because electrical current is carried by the

We can further subdivide electrolytes into //strong// and //weak//. The resulting solution is a strong conductor of electricity.  The resulting solution is a weak conductor of electricity.  The resulting solution does not conduct electricity. 
 * Strong Electrolytes **<span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">: completely dissociate into ions when in aqueous solution. <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">
 * <span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Weak Electrolytes **<span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">: partially dissociate into ions when in aqueous solution. <span style="font-size: 7.5pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">4 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">
 * <span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Non-Electrolytes **<span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">: do not dissociate into ions when in aqueous solution. <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">


 * <span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">1. All ionic compounds are //strong// electrolytes. **<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">
 * <span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2. Some acids and bases are strong electrolytes; many others are //weak//. **<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">
 * <span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">3. Most other molecules are //non-//electrolytes. **<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">

Hydration: The process in which an ion is surrounded by water molecules arranged in a specific manner.

<span style="font-size: 18pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; msofareastfontfamily: 'Times New Roman'; msoansilanguage: EN-US; msofareastlanguage: EN-US; msobidilanguage: AR-SA;">**<span style="color: #f39e16; font-family: 'Times New Roman', Times, serif;">4.2 Precipitation Reactions ** <span style="font-size: 12pt; color: #000000; line-height: 115%; font-family: 'Times New Roman', Times, serif;">A //precipitation reaction// occurs when water solutions of two different ionic compounds are mixed and an insoluble solid separates out of solution. The precipitate is itself ionic; the cation comes from one solution and the anion from another. To predict the occurrence of these reactions, we must know which ionic substances are insoluble in water.

In a chemical sense **precipitation** is the formation of an //insoluble product//, a **precipitate**, usually a solid, which separates from the solution. A common precipitate is an insoluble salt.

litre of solvent. (We may also express a salt’s ability to dissolve in terms of its solubility product, K <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">sp <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">. <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">11 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> ) Salts and other solutes fall into two (or three) qualitative categories: soluble, (slightly soluble) and insoluble.
 * Solubility = maximum amount of a solute that will dissolve in a given amount of a**
 * solvent //at a specific temperature//**. Solubility is typically given in grams of solute per
 * <span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Soluble **<span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">: ‘fair amount’ //visibly// dissolves when added to water. <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">
 * <span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Insoluble or slightly soluble **<span style="font-size: 12pt; color: blue; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">: no //noticeable// amount dissolves. <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">



<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">**Writing Balanced Reaction Equations** Pb(NO <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">3 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">) <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(**//aq//**) + 2 NaI (**//aq//**) à PbI <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(**//s//**) + 2 NaNO <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">3 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(**//aq//**) Pb <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2+ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 NO <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">3 <span style="font-size: 9pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">- <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 Na <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">+ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 I <span style="font-size: 9pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">- <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) à PbI <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(**//s//**) + 2 Na <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">+ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 NO <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">3 <span style="font-size: 9pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">- <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) Pb <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2+ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 NO <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">3 <span style="font-size: 9pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">- <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 Na <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">+ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 I <span style="font-size: 9pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">- <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) à PbI <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//s//) + 2 Na <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">+ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 NO <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">3 <span style="font-size: 9pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">- <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> Pb <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2+ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + 2 I <span style="font-size: 9pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">- <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) à PbI <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">2 <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//s//) Na <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">+ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) and NO <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">3 <span style="font-size: 9pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">- <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) <span style="font-size: 7.5pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> //<span style="font-size: 12pt; color: red; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">From the solubility rules you should be able to predict the products of a precipitation //<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> //<span style="font-size: 12pt; color: red; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">reaction and write a balanced reaction equation. //<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">
 * Molecular, Ionic and Net Ionic Equations; Spectator Ions**
 * Molecular equation:**
 * Ionic equation:**
 * Net ionic equation:**
 * Spectator Ions:**

<span style="font-size: 18pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">** 4.3 Acid-Base Reactions ** • Svante Arrhenius proposed the following definitions for acids and bases in 1884: – An **//Arrhenius acid//** is a substance that ionizes in water to produce hydrogen ions (H+). – An **//Arrhenius base//** is a substance that ionizes in water to release hydroxide ions (OH-). • For example, HCl is an Arrhenius acid and NaOH is an Arrhenius base. • To determine whether you have an Arrhenius acid or base, write the ionization or dissociation reaction of your compound. • The Brønsted-Lowry definitions of acids and bases are **broader** than the Arrhenius definitions.
 * Acid-Base Concepts**<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">
 * HA (aq) → H+ (aq) + A- (aq)**
 * MOH (aq) → OH- (aq) + M+ (aq)**

A **//Brønsted-Lowry acid//** is a substance that donates a hydrogen ion (H+) to any other substance. – It is a **//proton donor//**. – All Arrhenius acids are classified as acids by the B-L definition <span style="font-size: 10pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">

<span style="font-size: 12pt; color: black; line-height: 115%; font-family: Times New Roman; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; msofareastfontfamily: 'Times New Roman'; msoansilanguage: EN-US; msofareastlanguage: EN-US; msobidilanguage: AR-SA;">A **//Brønsted-Lowry base//** is a substance that accepts a hydrogen ion (H+). – It is a **//proton acceptor//** (So no OH- required!). – All Arrhenius bases are classified as bases by the B-L definition



<span style="font-size: 12pt; color: black; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman';">Acids and bases have varying strengths. • The strength of an **acid** is measured by the amount of H+ that are produced for each mole of acid that dissolves – **//Ionization//** is the process where polar compounds separate into cations and anions in solution. – The acid HCl ionizes into H+ and Cl– ions in solution. • The strength of a **base** is measured by the degree of dissociation in solution. – **//Dissociation//** is the process where cations and anions in an ionic compound separate in solution. – A formula unit of NaOH dissociates into Na+ and OH– ions in solution.

<span style="font-size: 12pt; font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">

<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">**Neutralization Reactions** A //neutralization reaction// is the reaction of an acid and a base to produce a salt (BX) and water (HOH). HX + BOH <span style="font-size: 12pt; color: #b90000; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">→ <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">BX + HOH –This is a specialized “double replacement” reaction • The driving force of this reaction is the formation of the stable water molecule. <span style="font-size: 12pt; color: #a60021; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">H <span style="font-size: 12pt; color: #33339b; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Cl <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + <span style="font-size: 12pt; color: #33339b; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Na <span style="font-size: 12pt; color: #a60021; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">OH <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) → <span style="font-size: 12pt; color: #33339b; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">NaCl <span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">(//aq//) + <span style="font-size: 12pt; color: #a60021; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">H2O(//l//)

–The formation of ionic solids from elements is always a Redox reaction. • The driving force of this reaction is the decrease in electrical potential. Mg(s) + I2(g) → MgI2(s) • The transfer of electrons between or among reactants is called the **oxidation** or **reduction** of species depending on which way the electrons are flowing. Types of Redox Reactions: <span style="font-size: 12pt; font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Disproportionation Reaction: an element in one oxidation state is simultaneously oxidized and reduced; Cl2 + 2OH- <span style="font-size: 12pt; font-family: Wingdings; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA; msofareastfontfamily: 'Times New Roman'; msoansilanguage: EN-US; msofareastlanguage: EN-US; msobidilanguage: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Wingdings; msoasciifontfamily: 'Times New Roman'; msohansifontfamily: 'Times New Roman'; msochartype: symbol; msosymbolfontfamily: Wingdings; mso-bidi-font-family: 'Times New Roman'; msobidifontfamily: 'Times New Roman';">à <span style="font-size: 12pt; font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> ClO- + Cl- + H2O
 * <span style="font-size: 18pt; color: #50d930; line-height: 115%; font-family: 'Times New Roman', Times, serif;">4.4 Oxidation-Reduction Reactions **<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman';">
 * •** An **Oxidation–Reduction (Redox) Reaction** is a process in which one or more electrons are transferred between reaction partners.
 * Reducing agent donates electrons
 * Oxidizing agent accepts electrons
 * An atom’s oxidation number, also called oxidation state, signifies the number of charges the atom would have in a molecule if electrons were transferred completely. They enable us to identify elements that are oxidized and reduced at a glance.
 * We use the following rules to assign oxidation numbers:
 * In free elements each atom has an oxidation number of zero.
 * For ions composed of only one atom, the oxidation number is equal to the charge on the ion.
 * The oxidation number of oxygen in most compounds is -2, but in hydrogen peroxide and peroxide ion, it is -1.
 * The oxidation number of hydrogen is +1, except when it is bonded to metals in binary compounds.
 * Fluorine has an oxidation number of -1 in ALL its compounds. Other halogens have negative oxidation numbers when they occur as halide ions in their compounds.
 * In a neutral molecule, the sum of the oxidation numbers of all the atoms must be 0. In a polyatomic ion, the sum of oxidation numbers of all the elements in the ion must be equal to the net charge of the ion.
 * Oxidation numbers do not have to be integers.
 * Combination Reactions: A + B <span style="font-family: Wingdings; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Wingdings; msoasciifontfamily: 'Times New Roman'; msohansifontfamily: 'Times New Roman'; msochartype: symbol; msosymbolfontfamily: Wingdings;">à C
 * Decomposition Reactions: C <span style="font-family: Wingdings; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Wingdings; msoasciifontfamily: 'Times New Roman'; msohansifontfamily: 'Times New Roman'; msochartype: symbol; msosymbolfontfamily: Wingdings;">à A + B
 * Displacement Reactions: A + BC <span style="font-family: Wingdings; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Wingdings; msoasciifontfamily: 'Times New Roman'; msohansifontfamily: 'Times New Roman'; msochartype: symbol; msosymbolfontfamily: Wingdings;">à AC + B
 * Hydrogen Displacement: Ca + 2H2O <span style="font-family: Wingdings; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Wingdings; msoasciifontfamily: 'Times New Roman'; msohansifontfamily: 'Times New Roman'; msochartype: symbol; msosymbolfontfamily: Wingdings;">à Ca(OH)2 + H2
 * Metal Displacement: V2O5 5Ca <span style="font-family: Wingdings; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Wingdings; msoasciifontfamily: 'Times New Roman'; msohansifontfamily: 'Times New Roman'; msochartype: symbol; msosymbolfontfamily: Wingdings;">à 2V + 5CaO
 * Halogen Displacement: Cl2 + 2KBr <span style="font-family: Wingdings; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Wingdings; msoasciifontfamily: 'Times New Roman'; msohansifontfamily: 'Times New Roman'; msochartype: symbol; msosymbolfontfamily: Wingdings;">à 2KCl + Br2


 * <span style="font-size: 18pt; color: #73b3f7; line-height: 115%; font-family: 'Times New Roman', Times, serif;">4.5 Concentration of Solutions **<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman';">

The **concentration of a solution** is the amount of solute present in a given quantity of solvent or solution.
 * Molarity (M), or molar concentration**, is the number of moles of solute in 1 liter (L) of solution
 * Dilution** is the procedure for preparing a less concentrated solution from a more concentrated one.

--> Moles of solute before dilution = moles of solute after diliution --> Moles of solute/liters of solution x volume of solution (in liters) = moles of solute --> MV = moles of solute --> MiVi = MfVf


 * Quantitative analysis** is the determination of the amount or concentration of a substance in a sample.

The quantitative determination of a substance by precipitation followed by isolation and weighing of the precipitate is called **gravimetric analysis**.

<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman';">
 * 4.6 Gravimetric Analysis **
 * Gravimetric analysis ** is an analytical technique based on the measurement of mass.


 * <span style="font-size: 18pt; color: #6a32e7; line-height: 115%; font-family: 'Times New Roman', Times, serif;">4.7 Acid-Base Titrations **<span style="font-size: 12pt; color: black; line-height: 115%; font-family: 'Times New Roman', 'serif'; mso-fareast-font-family: 'Times New Roman';">

In a **titration** a solution of accurately known concentration, called **standard solution**, is added gradually to another solution of unknown concentration, until the chemical reaction between the two solutions is complete. The **equivalent point** is the point at which the acid has completely reacted with or been neutralized by the base. In acid-base titrations, **indicators** are substances that have distinctly different colors in acidic and basic media.

<span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Like acid-base titrations, redox titrations normally require an indicator that clearly changes color. In the presence of large amounts of reducing agent, the color of the indicator is characteristic of its reduced form; in large amounts of oxidizing agent, oxidized form; and at equivalence point, oxidized or reduced. <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Potassium dichromate and potassium permanganate are internal indicators in a redox titration because they have distinctly different colors in the oxidized and reduced forms.
 * <span style="font-size: 18pt; color: #ef6ef7; line-height: 115%; font-family: 'Times New Roman', Times, serif;">4.8 Redox Titrations **

<span style="font-size: 18pt; color: #000000; font-family: 'Times New Roman', Times, serif;">LAB: Microscale Acid-Base Titration <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';"> **<span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Materials to be used ** <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Provided materials <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">5mL unknown acid sample <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">25mL .01 sodium hydroxide solution <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">10 x 10 graph paper Additional materials <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Safety materials: Goggles and aprons <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Plastic experimental wells, about 5mL deep <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Pipette <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Roll of litmus paper

<span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Wearing goggles and aprons to protect against splashes and burns, transfer about 1mL of the known base into a clean well. <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Take an initial pH reading with a strip of litmus paper. Record this in a table. <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">With a pipette, add one drop of the unknown acid solution to the well. Use another strip of litmus paper to test the new pH and record in the table. <span style="font-size: 12pt; font-family: Symbol; mso-fareast-font-family: Symbol; msofareastfontfamily: Symbol; mso-bidi-font-family: Symbol; msobidifontfamily: Symbol; msolist: Ignore;">· <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Continue to add a drop of acid and measure the pH, recording all data in the table. Once the equivalence point is reached, plot the data points on the graph paper. The y-axis quantifies acidity and the x-axis indicates the drops of acid added. Compare the resulting titration curve to the curves given by a strong base titrated with a strong acid and a strong base with a weak acid (since the provided alkali is NaOH, a strong base). From this comparison determine if the unknown acid is strong or weak.
 * <span style="font-size: 12pt; font-family: 'Times New Roman', 'serif';">Procedure **

<span style="font-size: 12pt; color: black; font-family: Helvetica; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">













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