Are you ready for the Advanced Training?

Transcription

1 Are you ready for the Advanced Training? Welcome to the World of Chemical Formulae This would be a second rate school if it did not attempt to extend its students as early as possible. This package aims to teach you some of the advanced skills of the chemist. It is not easy, but you may just be surprised at how good you will be at it later if you start early. The homework system is simple. You submit your first assignment and the teacher will record your attempt. As well as doing the next assignment, you are expected to resubmit the previous assignment with corrections in red. This allows you to learn from your mistakes Advanced skills 1 Advanced Extension 1

2 Data Table 1 Valence Reference Table Many elements have variable valence. This table shows the most common valence first, followed by less common valencies in brackets.. Element Symbol Type Valence Appearance Ion Old Name Aluminium Al Metal 3 Silver sol. Al 3+ Argon Ar NM 0 Colourless gas Barium Ba Metal 2 Silver solid Ba 2+ Bromine Br NM 1 Brown liq. Br - Calcium Ca Metal 2 Grey solid Ca 2+ Carbon C NM 4 (2) Black solid Chlorine Cl NM 1 Yellow-green gas Cl - Chromium Cr Metal 3(2,6) Silver blue sol Cr 3+ Cobalt Co Metal 2(3) Grey solid Co 2+ Copper Cu Metal 2(1) Brown solid Cu 2+ Cuprum Fluorine F NM 1 Green gas F - Gold Au Metal 3(1) Yellow solid Au 3+ Aurum Helium He NM 0 Colourless gas Hydrogen H NM 1 Colourless gas H + Iodine I NM 1 Purple grey solid I - Iron Fe Metal 3(2) Grey solid Fe 3+ Ferrum Lead Pb Metal 2(4) Grey solid Pb 2+ Plumbum Lithium Li Metal 1 Grey solid Li + Magnesium Mg Metal 2 Grey solid Mg 2+ Manganese Mn Metal 2(3467) Grey solid Mn 2+ Mercury Hg Metal 2(1) Grey liquid Hg 2+ Hydrogyrum Neon Ne NM 0 Colourless gas Nickel Ni Metal 2(3) Grey solid Ni 2+ Nitrogen N NM 3(542)Colourless gas Oxygen O NM 2 Colourless gas O 2- Phosphorus P NM 5(34) Brown solid Potassium K Metal 1 Grey solid K + Kalium Silicon Si Metal 4 Grey solid Silver Ag Metal 1 Silver solid Ag + Argentum Sodium N a Metal 1 Silver solid Na + Natrium Sulphur S NM 2(46) Yellow solid Tin Sn Metal 4(2) Silver solid Stannum Titanium Ti Metal 4(3) Silver solid Tungsten W Metal 6(5432) Grey solid Wolfram Uranium U Metal 6(543) Grey solid Zinc Zn Metal 2 Grey solid Zn 2+ Advanced skills 2

3 Data Sheet 2. Valencies to be Memorised by Advanced Chemists The following is a list of the most commonly used valencies. You would be wise to learn them all. The table also shows the ion charges. Metal Non metal Radical VALENCE 1 Sodium Na + Fluorine F - Ammonium NH + 4 Potassium K + Chlorine Cl - Hydroxide OH - Silver Ag + Bromine Br - Nitrate NO - 3 Hydrogen H + Iodine I - Bicarbonate HCO - 3 Bisulphate HSO - 4 VALENCE 2 Magnesium Mg 2+ Oxygen O 2- Sulphate Calcium Ca 2+ Sulphur S 2- Carbonate SO 2-4 CO 2-3 Barium Ba 2+ Zinc Zn 2+ Lead Pb 2+ Copper II Cu 2+ Iron II Fe 2+ Tin II Sn 2+ Mercury II Hg 2+ VALENCE 3 Aluminium Al 3+ Phosphate PO 3-4 Iron III Fe 3+ VALENCE 4 Carbon Silicon C Si How do you memorise things? The easy way is to set up a card system with the name on the front and the formula on the back. Shuffle your cards and practise. Advanced skills 3

4 Data Sheet 3 Radical Reference Table By now your mummy should have told you that radicals are pretty wierd. Caring societies tolerate them. Sometimes, for better or worse, we put them in charge. Usually they live on the fringe and belong there. Radicals are groups of covalently bonded atoms that tend to be stable together and often survive chemical reactions together. For this reason, we give the whole clump a name rather than naming the individual elements. All radicals are ions (with a charge). Most radicals are negatively charged and come second in the formula. The charge of the radical is its valence. Name Formula Name Formula AMMONIUM NH + 4 ACETATE CH 3 COO - CARBONATE CO 2-3 BICARBONATE HCO - 3 (hydrogen carbonate) CHLORATE ClO - 3 CHLORITE ClO - 2 CHROMATE CrO 2-4 DICHROMATE Cr 2 O 2-7 (bichromate) HYDROXIDE OH - HYPOCHLORITE ClO - MERCUROUS Hg 2+ 2 NITRATE NO - 3 NITRITE NO - 2 OXALATE C 2 O 2-4 HYDROGEN OXALATE HC 2 O - 4 PERCHLORATEClO - 4 PERMANGANATE MnO - 4 PEROXIDE O 2-2 SUPEROXIDE O - 2 PHOSPHATE PO 3-4 HYDROGEN PHOSPHATE HPO 2-4 DIHYDROGEN PHOSPHATE H 2 PO - 4 SULPHATE SO 2-4 BISULPHATE HSO - 4 (hydrogen sulphate) BISULPHIDE HS - SULPHITE SO 2-3 (hydrogen sulphide) BISULPHITE HSO - 3 Advanced skills 4

5 Element Formulae Old Johnny Dalton was one of my favourite blokes. He was a poor old primary schoolteacher. The upper money-obsessed classes who ruled didn't like him much because the man was smart and kept telling them how to do things better. The grumpy old peasant with the dirty old coat and the glasses became known as the father of modern chemistry. Dalton realised that there are two kinds of chemicals. The simple ones are called elements. We give elements symbols with one or two letters. The first letter is a capital and the second letter is small. When we hold a piece of the element copper in our hands, we should realise that it has only one type of atom in it - copper atoms. The second chemicals are more complex. We call them compounds. Compounds contain two or more elements bonded together. This first assignment is based on the first data page on page 2. It contains a list of all the commonly used elements that you should meet during your next 70 years on this planet. The names and symbols are given in the first two columns. Sometimes the symbols are weird. How on earth did sodium get to be Na? It should be So. The problem was that England has always been a migrant country. English is not a traditional language but a combination of Celtic, Germanic, Old English, Norse, French and Latin. Many foreign words crept into the chemistry. Some of them are shown in the last column. Worry about ion charges later. You will notice that most elements are metals. A few are non metals (NM). Set 1 Element Symbols Identify and write formulae for each of these elements given the clues:- 1. This is a valuable yellow metal. It has an aura like the sun. Chemistry began when mad people thought that there was a special chemical called the "philosopher's stone". Add the philosopher's stone to iron and you get lots of lovely yellow stuff and die rich. 2. This metal starts with Z and is used to coat sheets of iron to stop it rusting. 3. This is the main element in steel and used to be called Ferrum by the Romans. 4. This metal was called cuprum by the Romans after the island of Cyprus where they mined it to make bronze. 5. The Romans conquered Britain to get a supply of this metal from mines in Cornwall. They called it stannum and used it to make bronze for their silly helmets. 6. This very light gas is used in balloons and nuclear bombs. It is what the sun fuses in its core to make heat and light. It is also the most common element in the universe. Advanced skills 5

6 7. This is the only liquid metal and is deadly poisonous. We used to use it to polish hats and make "mad hatters" out of rich men. The metal was kept in a tube called a "weasel" - hence "pop goes the weasel." 8. This metal is grey and can be cut with a knife. It also explodes in water. It is natural and is found in salt. It's name starts with S. Get the hint! Helium atom 9. Good old plumbum was used to make plumb bobs. These were hung of the side of framework to help builders construct level walls. 10. This yellow non metal is used to make the acid found in car batteries. 11. This metal is very common in nature, but is very difficult to extract from its mineral ore which is called bauxite. Because of this, it used to be very rare and valuable. Now Australia earns much revenue by manufacturing it. It has valence 3 and is used to make drink cans. 12. This is an explosive metal that can be cut with a knife. It is extracted from fire ashes or "potash". The potash was added to fat to make soap. 13. This black non metal is one of the elements in your body, coal, and the air you breathe out. 14. This is the heaviest natural element and is slightly radioactive. It was used to make the Hiroshima atomic bomb. Because it is so dense, it was used as armour plating in tanks in the gulf war, and also on the tips of the artillery shells that they fired. The battlefields are now covered in slightly radioactive dust. 15. This is not a white powder used in swimming pools, but is a highly dangerous yellow-green poisonous gas used by the Germans to kill our soldiers in World War This is an even more dangerous non metal which is also a green gas. It is found in the (safe) compounds used to harden the teeth of children so that they don't have to endure the dental agonies that my generation suffered. 17. This element was not discovered on earth, but was first observed in the sun's atmosphere by a Vatican Priest-astronomer who was observing an eclipse. It was named after the word "helios", meaning sun. The sun makes this element out of hydrogen in nuclear fusion and will blow up when its core runs out of hydrogen. 18. This grey metal is present in two chemical compounds in your teeth and bones. 19. This purple-grey solid non metal can be dissolved in alcohol to make a valuable antiseptic that is still used in operations. 20. This grey metal was named after "Old Nick", the Devil, because it slowly poisoned the people who mined it. Silicon is an important the element in rocks Advanced skills 6

7 Solutions Set 1 1. Gold Au 2. Zinc Zn 3. Iron Fe 4. Copper Cu 5. Tin Sn 6. Hydrogen H 7. Mercury Hg 8. Sodium Na 9. Lead Pb 10. Sulphur S 11. Aluminium Al 12. Potassium K 13. Carbon C 14. Uranium U 15. Chlorine Cl 16. Fluorine F 17. Helium He 18. Calcium Ca 19. Iodine I 20. Nickel Ni. Writing Compound Formulae We are going to practise the first rule to help you write chemical formula. Concentrate and get it right! As you can see, I am watching you! Rule 1. Write the formulae for each name with the valence numbers in pencil at the top right hand corner. Cross the numbers over. Then rub out numbers at top and any ones at the bottom. eg Copper chloride 2 1 Valence numbers in pencil at top right Cu Cl 1 2 Crossed over Becomes CuCl 2 (One atom of copper married to two of chlorine). The valence numbers at the top and the one at the bottom of the copper is erased Set 2 Applying Rule 1 Use data tables 2 & 3 to help you write chemical formulae for :- 1. copper fluoride 2. lead iodide 3. Sodium chloride 4. Potassium oxide 5. aluminium chloride 6. iron (3) chloride (you are being told what valence of iron to use ) 7. Silver iodide 8. iron (3) sulphide 9. hydrogen sulphide 10. sodium sulphide 11. hydrogen chloride 12. phosphorous (5) oxide 13. nitrogen (I) oxide (laughing gas) 14. tin (2) fluoride 15. zinc bromide 16. nitrogen (3) iodide (touch powder) 17. potassium sulphide 18. silicon chloride 19. aluminium oxide 20. iron (3) oxide (ferric oxide) Advanced skills 7

8 Solutions Set 2 1. CuF 2 2. PbI 2 3. NaCl 4. K 2 O 5. AlCl 3 6. FeCl 3 7. AgI 8. Fe 2 S 3 9. H 2 S 10. Na 2 S 11. HCl 12. P 2 O N 2 O 14. SnF ZnBr 2 16.NI K 2 S 18. SiCl Al 2 O Fe 2 O 3 Rule 2. This is the second valence rule to help you write compound formulae. If you can divide the valence numbers at the top by a common multiple then do so. eg Then cross the new numbers over and rub out working as before. Copper oxide Socrates who died drinking the chemicals 2 2 becomes 1 1 Cu O Cu O 1 1 Answer CuO Set 3 Application of Rule 2 Write formulae for the following:- 1) calcium oxide 2) copper sulphide 3) lead (2) oxide 4) lead (4) oxide 5) silicon dioxide (ignore the di. It means two.) 6) carbon dioxide 7) carbon monoxide or carbon (2) oxide (ignore the mono. It means one ) 8) zinc sulphide 9) nitrogen (4) oxide 10) tin (4) oxide Advanced skills 8

9 Solutions Set 3 1. CaO 2. CuS 3. PbO 4.PbO 2 5. SiO 2 6.CO 2 7. CO 8. ZnS 9. NO SnO 2 Rule 3. This is the second valence rule to help you write compound formulae. If a valence number of 2 or more is brought down next to a radical, a bracket is placed around the radical with the brought down number outside the brackets. Otherwise brackets are omitted. eg 1. Copper hydroxide 2 1 Cu OH 1 2 A two is brought down next to the radical. The radical must be bracketed. Answer is Cu(OH eg 2 Copper sulphate 2 2 Cu SO 4 Rule 2 applies. The twos at the top are divisible by Cu SO Answer is CuSO 4 (The radical is not bracketed as a one was brought down.) eg 3 Copper nitrate 2 1 Cu NO Answer is Cu(NO 3 (The radical is bracketed as a two was brought down.) Advanced skills 9

10 Set 4 Application of Rule 3 Write symbols for the following:- 1. Copper carbonate 2. Copper bicarbonate 3. Aluminium hydroxide 4. Sodium hydroxide 5. Lead nitrate 6. Ammonium oxide 7. Ammonium hydroxide 8. Ammonium sulphate 9. Silver carbonate 10. Zinc hydroxide 11. Iron (3) hydroxide 12. Iron (2) sulphate 13. Calcium carbonate 14. Magnesium nitrate 15. Aluminium phosphate 16. Lead hydroxide 17. Sodium carbonate 18. Potassium bicarbonate 19. Calcium phosphate 20. Zinc sulphate Now we are going to mix them all up. If you can do these, you have mastered chemical formula. Set 5 The Promised Land Write symbols for the following:- 1. Silver sulphate 2. Ammonium sulphide 3. Nitrogen (2) oxide 4. Calcium sulphate 5. Hydrogen phosphate 6. Zinc carbonate 7. Hydrogen sulphate 8. Potassium carbonate 9. Ammonium carbonate 10. Aluminium sulphate 11. Copper (2) oxide 12. Iron (2) carbonate 13. Hydrogen nitrate 14. Aluminium iodide 15. Ammonium iodide 16. Potassium hydroxide 17. Magnesium sulphate 18. Magnesium phosphate 19. Iron (3) phosphate 20. Mercury (2) sulphide. Set 6 Rough Stuff Write formulae for the following :- 1) Lead nitrate 2) zinc bromide 3) silver oxide 4) ammonium hydroxide 5) iron (3) phosphate 6) copper hydroxide 7) iron (3) carbonate 8) calcium sulphate 9) magnesium carbonate 10) sodium sulphate 11) potassium carbonate 12) copper bisulphate 13) calcium chloride 14) ammonium phosphate 15) silver nitrate 16) aluminium sulphate 17) iron (2) oxide 18) silicon sulphide 19) tin (2) oxide 20) calcium bicarbonate Set 7 R U Tuff? Write formula for the following :- 1) Hydrogen phosphate 2) lead iodide 3) copper bicarbonate 4) lead (4) oxide (used in car batteries) 5) potassium oxide 6) silver sulphide 7) calcium bisulphate 8) potassium phosphate 9) copper phosphate 10) lead sulphate 11) zinc hydroxide 12) ammonium sulphide 13) calcium hydroxide 14) sodium hydroxide 15) potassium nitrate 16) copper bromide 17) tin (4) chloride 18) mercury (2) sulphide 19) gold (3) fluoride 20) aluminium bicarbonate. Advanced skills 10

11 Solutions Set 4 1. CuCO 3 2. Cu(HCO 3 3. Al(OH) 3 4. NaOH 5. Pb(NO 3 6. (NH 4 O 7. NH 4 OH 8. (NH 4 SO 4 9. Ag 2 CO Zn(OH 11. Fe(OH) FeSO CaCO Mg(NO AlPO Pb(OH 17. Na 2 CO KHCO Ca 3 (PO ZnSO 4 Solutions Set 5 1. Ag 2 SO 4 2. (NH 4 S 3. NO 4. CaSO 4 5. H 3 PO 4 6. ZnCO 3 7. H 2 SO 4 8. K 2 CO 3 9. (NH 4 CO Al 2 (SO 4 ) CuO 12. FeCO HNO AlI NH 4 I 16. KOH 17. MgSO Mg 3 (PO FePO HgS Solutions Set 6 1) Pb(NO 3 2) ZnBr 2 3) Ag 2 O 4) NH 4 OH 5) FePO 4 6) Cu(OH 7) Fe 2 (CO 3 ) 3 8) CaSO 4 9) MgCO 3 10) Na 2 SO 4 11) K 2 CO 3 12) Cu(HSO 4)2 13) CaCl 2 14) (NH 4 ) 3 PO 4 15) AgNO 3 16) Al 2 (SO 4 ) 3 17) FeO 18) SiS 2 19) SnO 20) Ca(HCO 3 Solutions Set 7 1) H 3 PO 4 2) PbI 2 3) Cu(HCO 3)2 4) PbO 2 5) K 2 O 6) Ag 2 S 7) Ca(HSO 4 8) K 3 PO 4 9) Cu 3 (PO 4 10) PbSO 4 11) Zn(OH 12) (NH 4 S 13) Ca(OH 14) NaOH 15) KNO 3 16) CuBr 2 17) SnCl 4 18) HgS 19) AuF 3 20) Al(HCO 3 ) 3 Advanced skills 11 Advanced extension 8

12 Formula Mastery Test Name Do your working on separate paper. Write your final formulae answers in the spaces provided:- 1. Sodium fluoride 11. Copper sulphate 2. Lead (4) oxide 12. Ammonium sulphate 3. Lead (2) oxide 13. Potassium sulphide 4. Zinc chloride 14. Silver nitrate 5. Copper nitrate 15. Calcium carbonate 6. Aluminium oxide 16. Magnesium hydroxide 7. Silver bicarbonate 17. Carbon (4) oxide 8. Potassium oxide 18. Ammonium phosphate 9. Hydrogen oxide 19. Zinc sulphide 10. Sodium carbonate 20. Sodium hydroxide Advanced skills 12

13 Be it Known to all that Has Mastered the Art of Writing Chemical Formulae Grade: Be it Known to all that Has Mastered the Art of Writing Chemical Formulae Grade: Advanced skills 13