# 0.4 Acid-base equilibrium

 Page 1 / 7

## Foundation

We have developed an understanding of equilibrium involving phase transitions and involving reactions entirely in the gas phase. We will assume anunderstanding of the principles of dynamic equilibrium, reaction equilibrium constants, and Le Châtelier's Principle . To understand application of these principles to reactions in solution, we willnow assume a definition of certain classes of substances as being either acids or bases. An acid is a substance whose moleculesdonate positive hydrogen ions (protons) to other molecules or ions. When dissolved in pure water, acid molecules will transfer ahydrogen ion to a water molecule or to a cluster of several water molecules. This increases the concentration of ${H}^{+}$ ions in the solution. A base is a substance whose molecules accept hydrogen ions from other molecules. When dissolved in pure water,base molecules will accept a hydrogen ion from a water molecule, leaving behind an increased concentration of $O{H}^{-}$ ions in the solution. To understand what determines acid-base behavior, we will assume an understanding of the bonding,structure, and properties of individual molecules.

## Goals

Acids and bases are very common substances whose properties vary greatly. Many acids are known to be quitecorrosive, with the ability to dissolve solid metals or burn flesh. Many other acids, however, are not only benign but vital to theprocesses of life. Far from destroying biological molecules, they carry out reactions critical for organisms. Similarly, many basesare caustic cleansers while many others are medications to calm indigestion pains.

In this concept study, we will develop an understanding of the characteristics of molecules which make themeither acids or bases. We will examine measurements about the relative strengths of acids and bases, and we will use these todevelop a quantitative understanding of the relative strengths of acids and bases. From this, we can develop a qualitativeunderstanding of the properties of molecules which determine whether a molecule is a strong acid or a weak acid, a strong baseor a weak base. This understanding is valuable in predicting the outcomes of reactions, based on the relative quantitative strengthsof acids and bases. These reactions are commonly referred to as neutralization reactions. A surprisingly large number of reactions,particularly in organic chemistry, can be understood as transfer of hydrogen ions from acid molecules to base molecules.

## Observation 1: strong acids and weak acids

From the definition of an acid given in the Foundation, a typical acid can be written as $HA$ , representing the hydrogen ion which will be donated and the rest ofthe molecule which will remain as a negative ion after the donation. The typical reaction of an acid in aqueous solutionreacting with water can be written as

$HA\left(\mathrm{aq}\right)+{H}_{2}O\left(l\right)\to {H}_{3}{O}^{+}\left(\mathrm{aq}\right)+{A}^{-}\left(\mathrm{aq}\right)$

In this reaction, $HA\left(\mathrm{aq}\right)$ represents an acid molecule dissolved in aqueous solution. ${H}_{3}{O}^{+}\left(\mathrm{aq}\right)$ is a notation to indicate that the donated proton has been dissolved in solution. Observations indicate that the proton isassociated with several water molecules in a cluster, rather than attached to a single molecule. ${H}_{3}{O}^{+}$ is a simplified notation to represent this result. Similarly, the ${A}^{-}\left(\mathrm{aq}\right)$ ion is solvated by several water molecules. [link] is referred to as acid ionization .

What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
how did you get the value of 2000N.What calculations are needed to arrive at it
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!