# 10.1 Conservation of matter  (Page 2/3)

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We will use two of our earlier examples of chemical reactions to demonstrate this:

1. The decomposition of hydrogen peroxide into water and oxygen

$2{\mathrm{H}}_{2}{\mathrm{O}}_{2}\to 2\mathrm{H}{}_{2}\mathrm{O}+{\mathrm{O}}_{2}$

Left hand side of the equation

$\mathrm{Total atomic mass}=\left(4×1\right)+\left(4×16\right)=68\phantom{\rule{2pt}{0ex}}\mathrm{u}$

$\mathrm{Number of atoms of each element}=\left(4×\mathrm{H}\right)+\left(4×\mathrm{O}\right)$

Right hand side of the equation

$\mathrm{Total atomic mass}=\left(4×1\right)+\left(4×16\right)=68\phantom{\rule{2pt}{0ex}}\mathrm{u}$

$\mathrm{Number of atoms of each element}=\left(4×\mathrm{H}\right)+\left(4×\mathrm{O}\right)$

Both the atomic mass and the number of atoms of each element are conserved in the reaction.

2. The synthesis of magnesium and oxygen to form magnesium oxide

$2\mathrm{Mg}+{\mathrm{O}}_{2}\to 2\mathrm{MgO}$

Left hand side of the equation

$\mathrm{Total atomic mass}=\left(2×24,3\right)+\left(2×16\right)=80,6\phantom{\rule{2pt}{0ex}}\mathrm{u}$

$\mathrm{Number of atoms of each element}=\left(2×\mathrm{Mg}\right)+\left(2×\mathrm{O}\right)$

Right hand side of the equation

$\mathrm{Total atomic mass}=\left(2×24,3\right)+\left(2×16\right)=80,6\phantom{\rule{2pt}{0ex}}\mathrm{u}$

$\mathrm{Number of atoms of each element}=\left(2×\mathrm{Mg}\right)+\left(2×\mathrm{O}\right)$

Both the atomic mass and the number of atoms of each element are conserved in the reaction.

## Materials:

1. Coloured marbles or small balls to represent atoms. Each colour will represent a different element.
2. Prestik

## Method:

1. Choose a reaction from any that have been used in this chapter or any other balanced chemical reaction that you can think of. To help to explain this activity, we will use the decomposition reaction of calcium carbonate to produce carbon dioxide and calcium oxide. ${\mathrm{CaCO}}_{3}\to {\mathrm{CO}}_{2}+\mathrm{CaO}$
2. Stick marbles together to represent the reactants and put these on one side of your table. In this example you may for example join one red marble (calcium), one green marble (carbon) and three yellow marbles (oxygen) together to form the molecule calcium carbonate ( ${\mathrm{CaCO}}_{3}$ ).
3. Leaving your reactants on the table, use marbles to make the product molecules and place these on the other side of the table.
4. Now count the number of atoms on each side of the table. What do you notice?
5. Observe whether there is any difference between the molecules in the reactants and the molecules in the products.

## Discussion

You should have noticed that the number of atoms in the reactants is the same as the number of atoms in the product. The number of atoms is conserved during the reaction. However, you will also see that the molecules in the reactants and products is not the same. The arrangement of atoms is not conserved during the reaction.

## Aim:

To prove the law of conservation of matter experimentally.

## Materials:

Test tubes; glass beaker; lead (II) nitrate; sodium iodide; hydrochloric acid; bromothymol blue; Cal-C-Vita tablet, plastic bag; rubber band; mass meter

Always be careful when handling chemicals (particularly strong acids like hydrochloric acid) as you can burn yourself badly.

## Method:

Reaction 1
1. Carefully weigh out 5 g of lead (II) nitrate.
2. Dissolve the lead nitrate in 100 ml of water.
3. Weigh the lead nitrate solution.
4. Weigh out 4,5 g of sodium iodide and dissolve this in the lead (II) nitrate solution.
5. Weigh the beaker containing the lead nitrate and sodium iodide mixture.
Reaction 2
1. Measure out 20 ml of sodium hydroxide.
2. Add a few drops of bromothymol blue to the sodium hydroxide.
3. Weigh the sodium hydroxide.
4. Weigh 5 ml of hydrochloric acid.
5. Add 5 ml of hydrochloric acid to the sodium hydroxide. Repeat this step until you observe a colour change (this should occur around 20 ml).
6. Weigh the final solution.
Reaction 3
1. Measure out 100 ml of water into a beaker.
2. Weigh the beaker with water in it.
3. Place the Cal-C-Vita tablet into the plastic bag.
4. Weigh the Cal-C-Vita tablet and the plastic bag.
5. Place the plastic bag over the beaker, being careful to not let the tablet fall into the water
6. Seal the bag around the beaker using the rubber band. Drop the tablet into the water.
7. Observe what happens.
8. Weigh the bag and beaker containing the solution.

#### Questions & Answers

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
The fundamental frequency of a sonometer wire streached by a load of relative density 's'are n¹ and n² when the load is in air and completly immersed in water respectively then the lation n²/na is
Properties of longitudinal waves