Group 17 Flashcards
Fluorine
Pale yellow gas
Chlorine
Yellow green gas
Bromine
Orange Brown liquid
Iodine
Shiny blue black crystals
Astatine
Black Solid
What happens to solid iodine when heated?
Solid iodine sublimes upon heating to give violet/purple vapours.
What is the trend in reactivity and oxisidising ability of group 17
The relative reactivities of halogens depends upon The electronegativity and the oxidizing ability a halogens. All halogens are oxidizing agents. The relative oxisidising ability decreases down a group hence the relative reactivity decreases down the group.
What are halide ions?
Halide ions are reducing agents. The relative reducing ability of halide ions increases down the group. Going down the group halide ions become larger, outermost electrons get further away from nucleus making it less tight to lose electrons and thus reducing agent increases.
Describe reaction with H2 gas
F2,Cl2,Br2 and I2 all react with H2 to form respective halogen halides. Cl(2)+H2(g)=2HCl(g)
The reactivity decreases down the group. All halogen highlights are colorless gases at RTP and when added to water form strong acids
What is the trend in thermal stability of hydrogen halides?
The thermal stabilities of hydrogen highlights decreases down the group. This is because the bond energy decreases as etch-X bond length increases. Fluorine atoms have a smaller bond enthalpy than chlorine and bromine because the atomic size of fluorine is smaller than that of chlorine and bromine making it easier for fluorine atoms to break bonds and escape the molecule.
What happens when a hot metal wire or hot glass rod is taken into a glass jar containing HI gas?
When a hot metal wire or hot glass rod is taken into a glass jar containing edge I gas, HI decomposes into H2 and i2, vapors since it is the least thermally stable. The same hot metal wire or glass will not decompose HBr or HCL.
Displacement reaction of halogens
The more reactive halogen can displace less reactive halogen from its highlights salt solution.
CL2 aquas Plus 2KL Aquos equals two KCL Aquos plus i2
Cl2 has oxidized i minus ions to i2 ions have reducl2 to CL- minus ions
What happens when acidified AGNO3 is added to an aqueous solution of CL - ions
When acidified AGNO3 is added to aqua solution of CL - ions a white precipitate of a AGCL forms.
When an excess of dilute aqueous NH3 is added the white precipitate dissolves completely
What is the use of fluorine
Used to make insulating handles for pans
What is the use of chlorine
Used for water purification and as bleaches agents
