8C.1 trends in group 7

Question 1

what forces does the boiling and melting points of halogens depend on and why

Answer 1

they depend on the intermolecular forces between the molecules since they are diatomic

Question 2

why dies the boiling point in halogens increase down the group

Answer 2

because there will be more electrons causing a greater electron density fluctuation causing a stronger instantaneous-induced dipole

Question 3

what is sublimation

Answer 3

it a solid changes directly to a vapor without melting

Question 4

what does the electronegativity of an atom depend on

Answer 4

1. the nuclear charge, the stronger the nuclear charge the more electronegative a species is
2. the inner energy level shielding, the less inner energy level shielding the more electronegative an element is
3. the distance between the nucleus and the bonding pair of electrons the shorter the distance the more electronegative an element is

Question 5

what is the trend of electronegativity in group 7

Answer 5

as you go down the group the electronegativity decreases

Question 6

what is the trend of temperature in group 7

Answer 6

the reactivity decreases down the group

Question 7

what is F in room temp

Answer 7

a gas

Question 8

what is Cl in room temp

Answer 8

gas

Question 9

what is Br in room temp

Answer 9

liquid

Question 10

what is I in room temp

Answer 10

solid

Question 11

what is As in room temp

Answer 11

solid

Question 12

what happens when you heat up an iodine

Answer 12

most of it sublimates into a purple vapor

Question 13

what happens when you leave Br in room temp or you heated

Answer 13

it would turn into a gas giving off brown vapour

Question 14

what is the colour of F

Answer 14

pale yellow

Question 15

what is the colour of Cl

Answer 15

yellow-green

Question 16

what is the colour of Br

Answer 16

red-brown

Question 17

what is the colour of I

Answer 17

dark purple

Question 18

what is the colour of As

Answer 18

black

Question 19

what is the trend of denisty going down the group

Answer 19

density increases down the group

Question 20

what is the trend of atomic radius

Answer 20

increases down the group

Question 21

what is the test for Cl

Answer 21

Blue litmus paper turns to red then bleach

Question 22

what is the color of Cl in water

Answer 22

colourless

Question 23

what is the colour of Br in water

Answer 23

yellow/orange

Question 24

what is the colour of I in water

Answer 24

brown

Question 25

what is the colour of I in hexene

Answer 25

pink/ violate

Question 26

what is the colour of Br in hexene

Answer 26

orange/red

Question 27

what is the colour of Cl in hexene

Answer 27

colourless

Question 28

what are the properties of group 7

Answer 28

they are poisonous, there nonpolar, they dissolve easily in organic compounds, they are oxidizing agents, and they are poor conductors

Question 29

why is it hard to study F and As

Answer 29

F it is a toxic gas

As is highly radioactive and decays quickly

Question 30

why is the bond enthalpy of F weaker than Cl even though it’s more electronegative

Answer 30

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

Question 31

why does the density increase down the group

Answer 31

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