oxygen Flashcards
characteristics of ozone
pale blue gas, pungent, forms blue solution in non polar solvents, slightly soluble in water
—- vigorous oxidising agent
test for oxygne in the lab
glowing splint test
how is oxygen collected in lab preps
water displacement as its less dense than water
methods of prep for oxygen
- decomposition of H2O2 using MnO2 (manganese IV oxide) H2O2 –> H2O + O2
- KClO3 heated with MnO2 to give O2 and KCl
- Na2O2 and water reaction to make NaOH and O2
- electrolysis of water
- heating oxides in high oxidation states : PbO2 to give PbO and O2
- heating metals low in the electrochemical series like Ag2O ang HgO;; Ag2O to give Ag and O2
show ozone acting as an oxidising agen
H2S + O3 —> H2SO4 + O2
PbS + O3 —> PbSO4 + O2
how oxygen can form both ionic and covalent compounds
oxygen atom can gain 2 electrons to form the oxide ion which results in ionic structures.
oxygen can also share 2 elecctrons to form 2 covalent bonds which results in simple molecules like CO2
H2O2 characteristics
- -pale blue liquid
- -powerful oxidising agent
- -thermally unstable
- -reducing agent with oxidants stronger than itself such as MnO4- to Mn2+ and Ag+ to Ag and Cr2O7 2- to Cr3+
- -readily decompose into free radicals ;homolysis due to weak peroxide bond
why is H2O2 unstable?
the single O-O bond is highly unstable and weak. due to repulsion of each electron dense cloud
lab prep of H2O2
action of hydrated barium peroxide on dilute H2SO4 or barium peroxide with phosphoric acid
peroxide ion
O2 2-
exmample sof mixed oxides
Fe3O4 ;; Fe2O3 and FeO
Pb3O4 ;;; PbO2.PbO
what is the superoxide ion, giev example of a superoxide and it’s reaction with water
O2 -
KO2
KO2+ H2O —> KOH and O2
sodium peroxide reaction with water and with CO2
Na2O2 + H2O —-> NaOH and H2O2
Na2O2 + CO2 —> Na2CO3 and O2
temporary and permanent hardness
temporary;; caused by hydrogen carbonates of calcium and Mg,, removed by boiling
permanent cause by Ca and Mg sulfates;; removed using washing soda by measn of ion exchange column
