OxygenOxygenLenka Šibravová, Lenka Šibravová,

Soňa KonečnáSoňa Konečná

OXYGENOXYGENthe element is very commonthe element is very commonmajor component of airmajor component of airthe second largest single component of the earth's the second largest single component of the earth's atmosphere (21% by volume)atmosphere (21% by volume)the atmosphere of Mars contains only about 0.15% oxygen the atmosphere of Mars contains only about 0.15% oxygen usually bound with other elementsusually bound with other elementsproduced by plants during photosynthesis produced by plants during photosynthesis necessary for aerobic respirationnecessary for aerobic respiration

plant = rostlina necessary = nutný, nezbytný plant = rostlina necessary = nutný, nezbytný bound = vázaný photosynthesis = fotosyntézabound = vázaný photosynthesis = fotosyntéza

PropertiesProperties• NameName:: OxygenOxygen • SymbolSymbol:: O O

• Atomic numberAtomic number:: 88

• Atomic weightAtomic weight:: 15.9994 15.9994

• Group numberGroup number:: 1616

• Group nameGroup name:: Chalcogen Chalcogen

• Period numberPeriod number:: 22

PropertiesPropertiesheavier than airheavier than air

soluble in watersoluble in water

without smell or tastewithout smell or taste

the gas is colourless, odourless and tasteless the gas is colourless, odourless and tasteless

chemical bonds with almost all other elements chemical bonds with almost all other elements

three isotopesthree isotopes

heavy = těžký soluble = rozpustný taste = chuť heavy = těžký soluble = rozpustný taste = chuť

PropertyPropertyliquid Oliquid O22 and solid O and solid O22 have a light blue color have a light blue color

highly paramagnetic highly paramagnetic

electronegativity electronegativity

highly oxidizing highly oxidizing

releasing heatreleasing heat

release = uvolnitrelease = uvolnit

liquid = kapalnýliquid = kapalný

solid = pevnýsolid = pevný

Liquid oxygenLiquid oxygen

PropertiesPropertiesthe shell structure of oxygen

crystal structure of oxygen.

HistoryHistory

• Discovered by:Discovered by: Joseph Priestley, Carl Scheele Joseph Priestley, Carl Scheele

• Discovered at:Discovered at: England, Sweden England, Sweden

• Discovered when:Discovered when: 1774 1774

Joseph PriestleyJoseph Priestley

PreparationPreparation• large number of different methods for its preparationlarge number of different methods for its preparation

1) Preparation of oxygen using potassium 1) Preparation of oxygen using potassium chloratechlorate

2 KClO2 KClO33 ==> 2 KCl + 3 O ==> 2 KCl + 3 O22

2) Preparation of oxygen using hydrogen 2) Preparation of oxygen using hydrogen peroxideperoxide

2 H2 H22OO22 ==> 2 H ==> 2 H22O + OO + O22

use = použítuse = použítpotassium = draslíkpotassium = draslík

PreparationPreparation

3) Preparation of oxygen by electrolysis of 3) Preparation of oxygen by electrolysis of waterwater

2 H2 H22O ==> 2 HO ==> 2 H22 + O + O22

4) Preparation of oxygen by the decomposition 4) Preparation of oxygen by the decomposition of salts of salts

2 KNO2 KNO33 ==> 2 KNO ==> 2 KNO22 + O + O22

5) Preparation of oxygen from air5) Preparation of oxygen from air

electrolysis of water = elektrolýza vodyelectrolysis of water = elektrolýza vodydecomposition of salts = rozklad solídecomposition of salts = rozklad solí

CompoundsCompounds

• oxygen is very reactiveoxygen is very reactive

• oxygen forms chemical bonds with almost all oxygen forms chemical bonds with almost all other elements other elements

• oxygen derivatives are prone to form free radicalsoxygen derivatives are prone to form free radicals

• the most common oxidation numbers are the most common oxidation numbers are -2-2

chemical bond = chemická vazbachemical bond = chemická vazba

prone = náchylný, nakloněnýprone = náchylný, nakloněný

free radicals = volné radikályfree radicals = volné radikály

oxidation numbers = oxidační číslooxidation numbers = oxidační číslo

CompoundsCompoundsHydroxideHydroxide Aluminium hydroxideAluminium hydroxide, , Al(OH)Al(OH)33

Barium hydroxideBarium hydroxide, , Ba(OH)Ba(OH)22

OxideOxide Carbon dioxideCarbon dioxide, , COCO22

WaterWater has the has the chemical formulachemical formula H2O

Alcohols (R-OH)Alcohols (R-OH) methanol, methanol, CHCH33OHOH

Methanol burns in air forming carbon dioxide and water:Methanol burns in air forming carbon dioxide and water:

2CH2CH33OH + 3 OOH + 3 O22 → 2CO → 2CO22 + 4H + 4H22O O

OzoneOzone

allotropic form of oxygen allotropic form of oxygen important component of the atmosphere important component of the atmosphere effect on the ozone layer effect on the ozone layer ozone is toxic! ozone is toxic! used for drinking water treatmentused for drinking water treatment

important = důležitý layer = vrstva important = důležitý layer = vrstva

drinking water = pitná voda treatment = léčbadrinking water = pitná voda treatment = léčba

ApplicationsApplications

oxygen is essential to respirationoxygen is essential to respirationused in medicine used in medicine used in welding used in welding making of steel and methanol making of steel and methanol

essential = nezbytný weld = svářet kovyessential = nezbytný weld = svářet kovy

steel = ocelsteel = ocel

Thank YouThank You