# 0.11 From cells and electrodes to golden pennies

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Protocol adapted from 'Chemistry in the Laboratory'

## Objective

The goal of this experiment is:

• Observe the deposition of zinc metal on a penny in contact with metallic zinc and to develop a hypothesis to explain how this happens.
• Observe how iron may be corroded or protected from corrosion depending on whether it is connected to copper or to zinc.
• Observe the plating of a penny with zinc and subsequent color changes.

You will be assessed on:

• completion of the report form.
• TA evaluation of lab procedure.

## Electrochemistry is everywhere

In general, whenever two condensed phases (solid or liquid) are brought into contact, a potential (or voltage) difference develops across the interface. Because the interface region is very thin, even transfer of a small amount of charge across the interface can create a very large electric field. For example, transferring about one picomole ( ${\text{10}}^{-\text{12}}$ mole) of electron charge per square centimeter of area will typically create a potential difference of approximately 1 volt across an interface layer about one nanometer thick. The electric field in this interface region would be about 109 volts/meter. Electric fields this large can cause the transfer of electrons across an interface layer or the transfer of ions between the inside and outside of ells in living organisms. Because contacts between condensed phases are very common in nature, electrochemical phenomena are very common, even though we are often unaware of them. At the cellular level, electrochemical phenomena are crucial to the propagation of nerve impulses, the timing of muscular contractions of the heart, and activity in your brain cells.

Most of the electrical technology created by humans involves the simplest kind of chemical change; electron transfer across an interface. Often, the interface is between a good electron conductor, called an electrode, and a solution containing molecules or ions. The electrode might be a solid (like platinum or copper metal or graphite), or it could be liquid (like mercury metal). When electrons are transferred from the electrode to a molecule, we say the molecule has been reduced. Electron transfer in the opposite sense (from molecule to electrode) is called oxidation.

There are two parts to this lab the first, ANODIC PROTECTION, you will perform in pairs. By coating steel (which is mostly iron metal) with a more active metal like zinc, a process called galvanizing, the steel's corrosion can be retarded or entirely prevented. Often, simply making a good electrical connection between a piece of iron and a piece of zinc is sufficient to keep the iron from corroding. We will study the acceleration and the prevention of iron corrosion by connecting it to various metals.

In the second part of this lab, we will be revisiting THE GOLDEN PENNY EXPERIMENT, which will be set up for you by your TA, so that you can make observations. As you remember, the golden penny experiment involves the plating of a penny with zinc metal. First, the penny is immersed in a solution containing 1 M NaOH and granular zinc. Subsequent heating of the penny for a few seconds on a hot plate causes the silver color of the penny to turn a bright golden yellow. Explaining the details of the process presents a challenge.

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
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
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