Izod L10

Question 1

Describe the Se, Te and Po hydrides

Answer 1

Hydrides are increasingly stable down group

Question 2

Describe the Se, Te and Po halides

Answer 2

EX2, EX4, EX6 (where X = F,Cl,Br)

Question 3

Describe the structure of SeF4

Answer 3

same structure as SF4 in gas phase. In solid state SeF4 units connected by F- - - Se contacts (extended structure)

Question 4

Describe group 17

Answer 4

ground state electronic configuration []ns2np5

Question 5

Describe the common oxidation states the group 17 adopt

Answer 5

-1, +1, +3, +5, +7

Question 6

How do we synthesise hydrogen fluoride

Answer 6

CaF2 + anhydrous H2SO4 -> CaSO4 + 2HF

Question 7

What does anhydrous HF do and write the equation

Answer 7

anhydrous HF etches glass:
4HF + SiO2 -> SiF4 + 2H2O
Cannot handle HF in glass

Question 8

Describe HF in aqueous solution

Answer 8

HF is a weak acid in aqueous solutions due to forming of undissociates H3O+F- ion pairs

Question 9

Describe the the inter halogen compounds

Answer 9

XY, XY3, XY5 and XY7 where x and y are different halogens

Question 10

Describe XY interhalogen species

Answer 10

all 6 possible combination known
- properties intermediate between X2/Y2

Question 11

Describe XY3 halogen species

Answer 11

ClF3, BrF3, IF3, ICl3

Question 12

Describe ClF3

Answer 12

One of the most ratioactive compounds known.
- ignites asbestos
- mostly used in uranium processing

Question 13

Describe the reaction for U processing

Answer 13

U + 3ClF3 -> UF6 + 3ClF
UF6 is volatile

Question 14

Describe the XY5 inter halogen compounds

Answer 14

XF5
Where X = Cl, Br, I

Question 15

Describe the XY7 interhalides known

Answer 15

only IF7 known

Question 16

What is the shape of XF7

Answer 16

pentagonal bipyramidal

Question 17

Describe the anionic polyhalides

Answer 17

formed when a halogen molecule reacts with a halide ion
Known polyhalides: I3^-, IBr2^-, ICl2^-, Br3^-, BrCl2^-

Question 18

What is the ground state for group 18

Answer 18

ground state electronic configuration ns2np6 - complete shell

Question 19

Describe group 18 chemistry

Answer 19

very very high activation energy

Question 20

Describe the known chemistry of group 18

Answer 20

Xe forms known XeFn compounds where n is a number

Question 21

What XeFn compounds can be formed

Answer 21

XeF2, XeF4, XeF6

Question 22

What reactions can XeF2 and XeF6 and write there equations

Answer 22

hydrolysis reactions
XeF2 + H2O -> Xe + 2HF + 1/2O2
XeF6 + 3H2O -> XeO3 + 6HF