8C.1 trends in group 7 Flashcards
what forces does the boiling and melting points of halogens depend on and why
they depend on the intermolecular forces between the molecules since they are diatomic
why dies the boiling point in halogens increase down the group
because there will be more electrons causing a greater electron density fluctuation causing a stronger instantaneous-induced dipole
what is sublimation
it a solid changes directly to a vapor without melting
what does the electronegativity of an atom depend on
- the nuclear charge, the stronger the nuclear charge the more electronegative a species is
- the inner energy level shielding, the less inner energy level shielding the more electronegative an element is
- the distance between the nucleus and the bonding pair of electrons the shorter the distance the more electronegative an element is
what is the trend of electronegativity in group 7
as you go down the group the electronegativity decreases
what is the trend of temperature in group 7
the reactivity decreases down the group
what is F in room temp
a gas
what is Cl in room temp
gas
what is Br in room temp
liquid
what is I in room temp
solid
what is As in room temp
solid
what happens when you heat up an iodine
most of it sublimates into a purple vapor
what happens when you leave Br in room temp or you heated
it would turn into a gas giving off brown vapour
what is the colour of F
pale yellow
what is the colour of Cl
yellow-green
what is the colour of Br
red-brown
what is the colour of I
dark purple
what is the colour of As
black
what is the trend of denisty going down the group
density increases down the group
what is the trend of atomic radius
increases down the group
what is the test for Cl
Blue litmus paper turns to red then bleach
what is the color of Cl in water
colourless
what is the colour of Br in water
yellow/orange
what is the colour of I in water
brown
what is the colour of I in hexene
pink/ violate
what is the colour of Br in hexene
orange/red
what is the colour of Cl in hexene
colourless
what are the properties of group 7
they are poisonous, there nonpolar, they dissolve easily in organic compounds, they are oxidizing agents, and they are poor conductors
why is it hard to study F and As
F it is a toxic gas
As is highly radioactive and decays quickly
why is the bond enthalpy of F weaker than Cl even though it’s more electronegative
it is because F is very small so the nonbonding pairs would repeal each other weaken the strength of the force even though it is more electronegative
why does the density increase down the group
as you go down the group the atomic radius increases causing the volume to increase therefore you can’t pack as many atoms in a given volume as the element before however, the element because heavier causing a more significant effect d=m/v
