The subject of this lesson is living in it own But people love to have it, and They destroy own future Only to be a master of it. What is it?… Lets.

The subject of this lesson is living in it ownBut people love to have it, andThey destroy own futureOnly to be a master of it. What is it?…

Let’s find a topic of the lesson guessing a

riddle!

?

2

«GOLD»

Au3

Topic of the lesson:

Identify the place of Gold in Mendeleev’s

periodic table

What we will learn from today’s lesson?

Determine physical

property of the gold

Introduce with dissolving process of

gold in aqua regia

Introduce with gold deposit, methods of gold mining and

assess current state of environmental pollution due

to gold mining

Learn how to deal in your living environment from the perspectives of what you learn from ESD programme, build up own responsibility to create safe environment for your and others living, create healthy environment for yourself and others.

Please identify where is the gold in chemical periodic system.

Place in periodic system

Group I• It belongs to clock D, 6th period

and group I• It is 79th element in periodic

system of chemical elements• Its standard atomic weight is

196,967• Its oxidation state are +1 and + 3• Its valency is I , III• Its electron configuration can

written as following: 1s22s22p63s23p63d104s24p64d104f14

5s25p65d106s1

Physical properties

• Gold has bright yellow color• It is most malleable metal and can be beaten

up to 0,0002mm thin.• It is melt in 106,3С • Its density is 19,3gr/cm3

• It is not oxidize in air

The chemical formula of gold dissolving process in aqua regia

2Au + 6HCl+ 2HNO3 = 2AuCI3 +2 NO + 4H2O

What is AQUA REGIA?

•3 HCl: HNO3 3 volumes of Hydrochloric acid : 1 volume of Nitric acid

10

Please write down the chemical formula of nitric acid compounding Aqua regia

electron configuration

:O :H :O: N :

:O

Structural configuration

O // H ─ O ─ N \\

O

Molecular configuration

HNO3

11

Please write down the chemical formula of hydrocloric acid compounding Aqua regia

Electron configuration

H :CI

Structural configuration

H ─ CI

Molecular configuration

HCI

.RANGE OF METALS BY THEIR ACTIVE REACTIONS

Active metals Inactive metals

• The purity of metal measured by millesimal fineness

• It is measured as parts per thousand of pure metal by mass in the alloy

• For example:– 97,5% silver is denoted as “975“– 75% gold is denoted as “750”

Worth to know

As exchange45%

For medals and awards2%

For coin making

19%

In juwellery14%

In elec-

tronics8%

For plat-ing teeth

6%

For plating7%

Rate of gold use in USA and some European countries, in percentage

To the history of gold use

• Human-being from the beginning knew the value of gold and rushed for gold.

• The history of wars and political battles mainly related to willingness of people to have be a master of all gold treasures of the world.

• As result many people even nations died because of high interest in gold. Lot’s of blood slaughtered just only one thing and it is gold

• Even now we can see how many people abandon their life and well-being just to find out a piece of gold.

Au use

Where the gold can be found?

Question 1

• Who are “ninja”-s or artesian miners? • What is an impact of gold mining? Are there

any examples?• Do you know what is a use of mercury?

Let’s discuss Mongolian mining and its impact

Possible solutions to reverse negative impact of gold mining

Solution Advantage Risk

Stop artesian miners The impact of illegal mining, especially application of inappropriate mining practices will be stopped

People involved in illegal mining will operate in more hidden manner

Develop new technology for gold mining

Creates possibilities to decrease negative impact of gold mining

Developing new technology needs time and resources

Enforce technological procedures during the gold mining, implement rehabilitation activities after mining

It is possible to implement due to some promising technologies are already exist and the legislations put in force

Law enforcement in Mongolia is terrible, therefore it might not be implemented.

Your solution? ........................ ....................................

Test1. What is gold number in periodic system?А. 109 Б. 79 В. 472. Which group belongs gold, silver, copper? А. I A b. II A c. I B d. II B3. How many base acids compounds Aqua regia?БА. 1 base . 2 base в. 3 base4. What is a place of gold in a range of metal active reactions comparing to

hydrogen?А. Before б. Behind5. Who is author of the “Golden fish”tale? А. Б.Ринчен Б. Л. Н. Толстой В. А.С. Пушкин6. What kind phrase is “Brass can shine near the gold”? А. idiom б. folksay в. riddle

Conclusions