Identify the place of Gold in Mendeleevs periodic table What we will learn from todays 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 79 th 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: 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 4f 14 5s 2 5p 6 5d 10 6s 1
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 106,3 С Its density is 19,3gr/cm 3 It is not oxidize in air
The chemical formula of gold dissolving process in aqua regia 2Au + 6HCl + 2HNO 3 = 2AuCI 3 +2 NO + 4H 2 O
What is AQUA REGIA? 3 HCl: HNO 3 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 HNO 3
11 Please write down the chemical formula of hydrocloric acid compounding Aqua regia Electron configuration H :CI Structural configuration H CI Molecular configuration HCI HCI
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
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. Lots 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.
Possible solutions to reverse negative impact of gold mining SolutionAdvantageRisk Stop artesian minersThe 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?............................................................
Test 1. What is gold number in periodic system? А. 109 Б. 79 В. 47 2. Which group belongs gold, silver, copper? А. I A b. II A c. I B d. II B 3. How many base acids compounds Aqua regia? БА. 1 base. 2 base в. 3 baseА. 1 base. 2 base в. 3 4. What is a place of gold in a range of metal active reactions comparing to hydrogen? А. Before б. А. Before б. Behind 5. Who is author of the Golden fishtale? А. Б.Ринчен Б. Л. Н. Толстой В. А.С. Пушкин 6. What kind phrase is Brass can shine near the gold? А. idiom б. folksay в. riddle