# Presentation: 212090

## Aqueous Reactions

*Dr. Ron Rusay*
*Spring 2002*

## Aqueous Reactions

*There are several general types:*
*	**	**1) ****Precipitation: ****An insoluble salt forms from the addition of solutions. ****(Refer to Solubility Rules)***
*	**	**2) ****Acid-Base Reactions (Neutralization) ****generally produces a salt plus water*
*	**	**3) ****Oxidation-Reduction (Redox) ****there is a change in oxidation numbers between reactants and products*

## Solution Test Apparatusfor Electrolytes 

* *

## Electrolytes

*Aqueous solutions can be categorized into 3 types: non-electrolytes, strong electrolytes or weak electrolytes based on their ability to conduct electricity.*
*A solution must have ****ions ****to conduct.*
***Pure Water ****does not conduct.*
*Aqueous solutions can be tested for conductivity which will determine the degree of ionization of the solutes.*
*It is possible to have full or partial ionization.*

## Electrolytes

*Almost all ionic compounds and a few molecular compounds are strong electrolytes.*
*Several  molecular compounds are weak conductors, most are non-conductors.*
*Conductivity is directly related to the amount of ionization, i.e. ions in solution. Table salt, sodium chloride, is completely ionized:*
***  ******NaCl******(s)****** + H******2******O******(l)****** ---> NaCl******(aq)****** --->         ****0.10M****	******	******	******Na****** ******+******(aq)****** + Cl ******-******(aq)****** ****0.00M**** ******	******	******	****0.10M    0.10M****	***

## Electrolytes

*** ****Concentrations:*
***CaCl******2 ******(s)****** + H******2******O******(l)****** ---> CaCl******2(aq)****** --->         ****0.10M****	******	******	******Ca****** ******2+******(aq)****** + ******2****** Cl ******-******(aq)****** ****0.00M**** ******	******	******	****0.10M    0.20M****	***

## Electrolytes

*Sugars like sucrose are non-ionic, molecular compounds that dissolve but produce no ions.*
***C******12******H******22******O******11 (S)****** + H******2******O******(l)****** ----> C******12******H******22******O******11 (aq)***
*Some molecular compounds like acetic acid ionize partially (dissociate) in water*
***HC******2******H******3******O******2 (l)****** + H******2******O******(l)******    H******3******O******+******(aq)******+ ******	****     0.1000M****	******	******         C******2******H******3******O******2 ******-******(aq)****** ***
*	**0.9987M**	**	**0.0013M*

## Aqueous Bases

*Any compound that accepts a proton is a base.*
*The common bases are group IA & IIA metal hydroxide compounds. They are strong bases, dissociating completely in water.*
*An example of a weak base is ammonia.*
***NH******3 (g)****** + H******2******O******(l)******     NH******3 (aq)******	******    NH******4******+******(aq)******+ ******	******	******	******	******	******	******OH******-******(aq)***

## Aqueous Reactions: Neutralization Net Ionic Equations

***HCl******(aq)****** +******  ******NaOH ******(aq)****** ---> NaCl ******(aq)****** + H******2******O******(l)***
*** ******___________________________________________________***
***HCl******(aq)****** --->  H******+******(aq)****** + Cl ******-******(aq)***
***NaOH ******(aq)****** ---> Na******+******(aq)******+ OH******-******(aq)***
***NaCl ******(aq)****** ---> Na******+******(aq)******+ Cl******-******(aq)***
*** ******________________________________________________***
***Na******+******(aq)******+ OH******-******(aq) ******+******  ******H******+******(aq)****** + Cl ******-******(aq) ******---> Na******+******(aq)******+ Cl******-******(aq) ******+ H******2******O******(l)***
*** ******_______________________________________________________***

***H******+******(aq)****** + OH ******-******(aq) ******---> H******2******O******(l)***

## Aqueous Reactions: PrecipitationNet Ionic Equations

*50mL of a 0.1M solution of sodium sulfate is mixed with 50mL of a 0.2M solution of silver nitrate. What is the result?*
*Molecular Equation:*
*** ******?Na******2******SO******4(aq)******+ ?AgNO******3(aq)****** ---> ***
***	******      ******	******	***
***	******	******	******?Ag******2******SO******4(s)  ******+ ?NaNO******3(aq)******	******	******	***_***	***__***	***_

_***1***_

_***2 ***_

_***1***_

_***2 ***_

## Aqueous Reactions: Precipitation

*Net Ionic Equations*

***Na******2******SO******4(aq)******+ 2 AgNO******3(aq)******-->Ag******2******SO******4(s)******+ ******	******	****0.1M****	******	****0.2M****	******	****** ******	******   2 NaNO******3(aq)***
*Ionic Reaction (Reactants):*
***Na******2******SO******4(aq) ************	***_***2***_*** Na******+******(aq)****** + SO******4******2-******(aq)***
*** ***_***2***_*** AgNO******3(aq) ************  ***_***2***_*** Ag******+******(aq)****** + ***_***2 ***_***NO******3******1-******(aq)***
***2 Na******+******(aq)******+ SO******4******2-******(aq)******+ 2 Ag******+******(aq)******+ 2 NO******3******1-******(aq)***
* **0.2M**	**	**0.1M**	**	**0.2M**	**	**  0.2M*

## Aqueous Reactions: Precipitation

*Net Ionic Equations*

***Na******2******SO******4(aq)******+ 2 AgNO******3(aq)******-->Ag******2******SO******4(s)******+ ****0.1M****	******	******	****0.2M****	******	****** 2 NaNO******3(aq)***
*Ionic Reaction (Products):*
***2 NaNO******3(aq) ************ ******	***_***2***_*** Na******+******(aq)****** + 2 NO******3******1-******(aq)***
*** ******Ag******2******SO******4(s) ************ ******Does not dissolve (ionize)***
***2Na******+******(aq)******+ 2NO******3******1-******(aq) ******+ Ag******2******SO******4(s)***
*** ****0.2M**	**	** 0.2M**	**	**    solid *

## Aqueous Reactions: Precipitation

*Net Ionic Equations*

***Na******2******SO******4(aq)******+ 2 AgNO******3(aq)******-->Ag******2******SO******4(s)******+ ******	******	******	******	******	******	****** ******	******2 NaNO******3(aq)***
*Overall Ionic Reaction:*
***2Na******+******(aq)******+ SO******4******2-******(aq) ******+2Ag******+******(aq)******+ 2NO******3******1-******(aq) *********
***2Na******+******(aq)****** + Ag******2******SO******4(s) ******+ 2NO******3******1-******(aq) ***
*Net Ionic Equation: (Subtract Spectator Ions)*

***2Ag******+******(aq)******+ SO******4******2-******(aq)     ************ ******     ******Ag******2******SO******4(s) ***

***= M******Na2SO4 ******xV******Na2SO4 ****** / 1:1******stoichiometry***

***= 0.10M x 0.050 L/  1***
***= 0.0050 mol***

*How many moles?*