Chlorine Chapter

8/8/2019 Chlorine Chapter

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ChlorineThis PowerPoint was brought to you by the the atomic symbol Cl



Physical Properties

Chlorine is a dense gas with a density of 3.21 grams per liter. By comparison, the

density of air is 1.29 grams per liter.

Chlorine changes from a gas into a liquid at a temperature of -34.05rC (-29.29rF) and

from a liquid to a solid at -101.00rC (-149.80rF).

The gas is soluble (dissolvable) in water.

It also reacts chemically with water as it dissolves to form hydrochloric acid (HCl) and

hypochlorous acid (HOCl).



Chemical Properties

Chlorine is a very active element. It combines with all elements except the noble

gases.

The reaction between chlorine and other elements can often be vigorous. For

example, chlorine reacts explosively with hydrogen to form hydrogen chloride.

Chlorine does not burn but, like oxygen, it helps other substances bum. Chlorine is a

strong oxidizing agent



The fine print

Chlorine is green and actually named after khlôros, the greek word for green.

Boiling Point: -34.6 rC (238.55 rK, -30.279997 rF)

Number of Protons/Electrons: 17

Number of Neutrons: 18

Classification: Halogen

Crystal Structure: Orthorhombic

Density @ 293 K: 3.214 g/cm3

Atomic Symbol: Cl

Atomic Weight: 35.453



Position of Chlorine in the Periodic Table



Arrangement of Electrons in Chlorine

The arrangement of the electrons in chlorine is 2, 8,

7 (i.e. 2 in the first shell, 8 in the second shell and 7in the third or outer shell). This means that they are

not stable, but they need to gain one electron to

the outer shell to complete the octet & make the

chlorine atom stable.

The arrangement of electron in Chlorine

atom is 1s2 2s2 2p6 3s2 3p5.

The atomic number of an atom gives the

number of protons and hence the number

of electrons. Since the atomic number of

Chlorine is 17, there are 17 electrons in a

chlorine atom.



Order of Filling Sublevels with Electrons in

Chlorine Atom

The number of electrons that

can fit into each s subshell is 2

for the first, 6 (2 + 4) for the p

subshell and 10 electrons(6 +

4) for the d subshel and so

on. The order filling of electrons in different

subshells can be obtained by

placing diagonal arrows

through the subshell pattern,

as shown.



iscovery

Chlorine was discovered in 1774 by Swedish chemist Carl Wilhelm Scheele (1742-86).

Scheele mixed pyrolusite (consists primarily of manganese dioxide (MnO2) with

hydrochloric acid (HCl). He found that a greenish-yellow gas with a suffocating odor

"most oppressive to the lungs" was released. The gas was chlorine. He mistook the

gas to be an oxide of the acid and hence named it Oxymuriatic Acid.

In 1800, Humphry David, identified it as an element and gave it the name chlorine

from its greenish color. [Greek Chloros means green]

Chlorine is termed as a Halogen; in Greek Halogen means a salt producer on account

of the fact that all halogens occur as salt.



Occurrence

Chlorine occurs commonly both in the Earth's crust and in seawater. Its abundance in

the earth is about 100 to 300 parts per million. It ranks 20 th among the elements in

abundance in the earth. Its abundance in seawater is about 2.6%.

The most common compound of chlorine in seawater is sodium chloride. Smaller

amounts of potassium chloride also occur in sea water.

Chlorine does not occur in the free state due to its highly reactive nature, high

electro negativity and salt forming tendency.

Chlorine combines with metals and nonmetals forming corresponding chlorides



Preparation of Chlorine

From concentrated hydrochloric acid by oxidation



A Quick Question

What does a computer, ablood bag, and aEcuadorian tree frog havein common?



The answer is of course,

Chlorine. Come on now,

isnt that what my

powerpoint is about?

Truth is, chlorine is used

in the making of

computers and bloodbags, and is also found inthe skin of theEcuadorian tree frog.

This is why the

chlorine industry choseChlement theEcuadorian tree frog tobe its symbol for promoting the benefitsof chlorine as a

product.



Some cool facts

Chlorine is found in

the Earth itself and, assalt, in the seas whichcover seven tenths ofthe planet.



More facts

Worldwide, waterborne diseases kill over 25,000

people each day. Drinking water chlorination is one

of the most widely used methods to safeguard andprotect drinking water supplies.

Its fundamental to the life of plants and animals.

Nature and chlorine can do some remarkablethings, like making a painkiller 200 times morepowerful than morphine but with no side-effects -all part of the natural defenses of the Ecuadorian

tree frog.



They keep coming...

Naturally occurring chlorine compounds arefound in our blood, skin, teeth and, also in theform of hydrochloric acid, in our digestivesystem.

In addition to water disinfection (pools),chlorine and its derivatives are used to treat

sewage and industrial effluent, and ashousehold and industrial bleaches to maintainand improve hygiene standards.



Its in your car.

Chlorine is an essential intermediate in the

production of polycarbonates and

polyurethanes.These important polymers areused to manufacture telecommunications andelectronic equipment, and to produceelectrical goods, automotive parts, sports

equipment, and even compact discs.



Facts continued... Chlorine-containingcompounds are

important factors in the

manufacture of Vitamin

C.

Discovered in 1774 by

Scheele, who believed it

contained oxygen.

Chlorine was named in1810 by Davy, who

insisted it was an

element.



Whats it for?

Chlorine is also extensively used in the

production of paper products, dyestuffs,textiles, petroleum products, medicines,antiseptics, insecticides, food, solvents, paints,plastics, and many other consumer products



How to handle it?

Chlorine is a respiratory irritant. The gasirritates the mucus membranes and the liquidburns the skin. As little as 3.5 ppm can bedetected as an odor, and 1000 ppm is likely tobe fatal after a few deep breaths. In fact,chlorine was used as a war gas in 1915.

Exposure to chlorine should not exceed 0.5ppm (8-hour time-weighted average - 40 hour week.) So dont live in the pool, okay?

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