halogens

Question 1

student mixes aqueous solution of chlorine and aqueous solution of sodium iodide

Answer 1

colour changes from colourless to brown as cl replace iodine due to formation of iodine so chlorine more reactive so will replace

Question 2

a student is given aqueous soltion of chlorine and a aqueous solution of sodium iodide explain how the student can use these solutions to compare the reactivity of chloroine with the reactivity of iodine

Answer 2

add chlorine solution to sodium iodide solution stir solution turn brown as iodine displace so chlorine more reactive than iodine

Question 3

aqueous chlorine is addes to seprate aqueous solutions of sodium chloride and sodium iodide explain how the observations made can be used to distingush between sodium chloride and sodium iodode

Answer 3

no change with sodium chloride but change brown with sodium iodide

Question 4

bromine reacts with hydrogen to form hydrogen bromide describe colour change

Answer 4

from orange to colourless

Question 5

a sample of hydrogen bromide is dissolved in water a piece of blue litmus papper is placed in the solution state with a reason.the final colour of litmus paper

Answer 5

colour is red because it formed ionization of h+

Question 6

suggest why it is nessecary to have an open tube fitted in apparatus

Answer 6

to avoid gas pressure

Question 7

for safety reasons this reaction should be carried out in fume cupboard explain why this is nessacry

Answer 7

chlorine is toxic gas

Question 8

state why the teatcher does not add bromine solution to sodium bromide solution

Answer 8

because bromine cant replace itself

Question 9

how is hydrogen chloride gas converted into hydrochloric acid

Answer 9

add to water

Question 10

state why chlorine is sometimes added to water supplies

Answer 10

to purfy it as it is seterllised agent

Question 11

suggest why the student does not need to add bromine solution to sodium bromide solution

Answer 11

bromine cant displace itsself

Question 12

observation when add damp blue litmus paper[chlorine]

Answer 12

bleaches

Question 13

observation when chlorine into a solution of pottasium iodide

Answer 13

brown

Question 14

write a chemical reaction to show the formation of hydrogen chloride from hydrogen and chlorine

Answer 14

h2+cl2=2hcl

Question 15

when water is added to this mixture and it is shaken a reaction occurs explain observations

Answer 15

bubbles of gas as in water h+ ions are formed so mg reacts to form hydrogen gas

Question 16

colour of fluroine when g and aq and ions

Answer 16

yellow,colourless,colourless

Question 17

colour of chlorinr when g and aq annd ions

Answer 17

green,yellow,colourless

Question 18

colour of bromine when g and l and aq and ions

Answer 18

orange,brown,red or orange,colourless

Question 19

colour of iodine when g,s,aq,ions

Answer 19

purple,dark grey,bown,colourless

Question 20

colour of astatine when solid and ions

Answer 20

black,colorless

Question 21

uses of fluorine

Answer 21

it is used in water supply and in toothpaste to prevent the decay of the enamel of the tooth

Question 22

uses of chlorine

Answer 22

in purfication of drinkable water as it is a sertiizing agent,making bleach,production of some plastics such as pvc,production of hydrochloric acid,production of bromine

Question 23

uses of iodine

Answer 23

it is used as antiseptic

Question 24

general proprties of halogens

Answer 24

they are diatomic elements
halogens are strong oxidising agents as they have high tendency to gain electrons
bromine very voltaile so easily turn into gas
hqlogens are very active elements as fluroine most reactive
outermost energy level of halogen contains 7 electron

Question 25

why reactivity decreases from up to doWN along this group why?

Answer 25

as the atoms get larger the outer most shell gets further from the nueclud attraction between the nucleus and electron in the outershell gets weaker so an electron is less easily gained

Question 26

why hydrogen chloride is gas

Answer 26

because the molecules are bonded by weak inter molecular force

Question 27

Is noble gas monoatomic or diatomic

Answer 27

Monoatomic

Question 28

Is halogen monoatomoc or diaotomic

Answer 28

Diatomic