group 7

what happens to the electronegativity of halogens down the group

decrease because atomic radius increases, distance between nucleus and bonding pair of electrons increases, less energy to remove

what happens to the reactivity down the group

decreases as atomic radius increases, distance between nucleus and outer shell of electrons increases, attraction between them decreases, harder to gain an electron

what do the halogens act as when they react

oxidising agents, as they gain electrons and are reduced

explain the bond enthalpy from flurine to iodine

from chlorine to iodine the bond enthalpy decreases because the atomic radius is larger, so the distance from the nuclei to bonding pair of electrons increases, so weaker attraction and the orbitals also overlap less effectively leading to weaker attraction. Florine is lower because its so small, the bonding pair of electrons in the outer shell repel

what's the reaction between halogens and group 1/2 metals

form metal halides, which are white, ionic solids

What is the reaction between chlorine, bromine and iodine with cold sodium hydroxide

forms sodium chloride, sodium chlorate (1) and water

what's the reaction between chlorine, bromine and iodine with hot sodium hydroxide

forms sodium chloride, sodium chlorate (V) and water

what are the reaction between the halogens and sodium hydroxide examples of

disproportionation

what is the reaction between chlorine and potassium iodide

forms potassium chloride and iodine solution

how would you test for the iodine solution

add hexane and a lilac band should appear

what are the only two colours you will see in a displacement reaction of halogens if you add hexane

orange and lilac because iodine and bromine are the least reactive

describe the boiling point of the hydrogen halides

hydrogen fluoride has the highest because it has has hydrogen bonds between molecules. Strongest IMF Boiling point increases from HCl to HI as there are more electrons, so the London forces are stronger

what is the test for chloride ions

add silver nitrate and nitric acid. A white precipitate should appear

what is the test for bromine ions

add silver nitrate and nitric acid. A cream precipitate should appear

what is the test for iodine ions

add silver nitrate and nitric acid. A yellow precipitate should appear

describe what hydrogen halides look like

they are colourless gases that form misty fumes when they are in moist air

what do hydrogen halides form in water

Form acids HF forms a weak acid HCl and HBr form stronger acids

what happens when you mix hydrogen halides and ammonia

You dip a rod in ammonia and put it into the misty fumes to make an ammonium halide salt.

what does an ammonium halide salt look like

appears as white smoke but is actually very fine powder (solid)

how do you find if carbonate ions or hydrogen carbonate ions exist

add a dilute acid and carbon dioxide will form. Turns limewater cloudy

what is the test to find the presence of sulphate ions

add dilute hydrochloric acid add barium chloride a white precipitate should form

what is the test to find the presence of ammonium ions

add sodium hydroxide and ammonia should be produced. If dipped in damp red litmus paper it turns blue

which halogen is the best oxidising agent

fluorine because it has the smallest atomic radius and will be reduced and gain electrons easier

which halogen is the best reducing agent

iodine because it will lose electrons and oxidise as it has the largest ionic radius

why is the reaction between chloride ions and conc. sulfuric acid non redox

its a non-redox reaction because chlorine isn't a strong enough reducing agent.

what are the products of the reaction between Sulfuric acid and chloride ions

Produces a hydrogen chloride (misty fumes) and XHS04 where X is a metal

what is the reaction between bromide ions and concentrated sulfuric acid

non redox- HBr (misty fumes) and XHS04 redox - S02 and Br2 and H20 formed

what is S02

sulfur dioxide is a colourless, choking gas

what will the bromine look like

a brown liquid/ orange fumes

What are the redox reactions between iodide ions and concentrated sulfuric acid

redox - S02 + I2 + H20 redox- S + I2 + H20 redox - H2S + I2 + H20

what does the iodine appear as

a black solid with purple fumes

what does the sulfur look like

a yellow solid

what does the H2S appear as

a colourless eggy gas

What colour is iodine as a solid

shiny grey

What colour is iodine in water

brown

why can fluorine form hydrogen bonds but iodine can't

fluorine is more electronegative as it has less shielding and a smaller atomic radius due to less shells. So HF is more polar

Why does water have a higher boiling point then HF

Water can form up to 2 hydrogen bonds but HF can only form 1

which 2 halogens are gases at room temp

Fluorine and chlorine

what colour is fluorine everywhere

pale yellow

what colour is chlorine everywhere

pale green

what colour is bromine at room temp

brown liquid

what state is bromine in at room temp

liquid

What state is iodine and astatine at room temp

solid

what colour is iodine at room temp

black solid (with purple vapours when heated)

what colour is iodine in water

brown

What colour is iodine in hexane

purple

What colour is astatine at room temp

black solid

What colour is bromine in water

Orange/brown

Wha colour is bromine in hexane

Orange

If you want to form Hydrogen Iodide from Potassium iodide why wouldn't you add conc sulfuric acid

The conc sulfuric acid is too strong of an oxidising agent and will form Iodine

What would happen if you inverted a test tube of Hydrogen iodide gas into water

the gas would dissolve

What state is ammonia at at room temp

gas