halogens Flashcards
student mixes aqueous solution of chlorine and aqueous solution of sodium iodide
colour changes from colourless to brown as cl replace iodine due to formation of iodine so chlorine more reactive so will replace
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
add chlorine solution to sodium iodide solution stir solution turn brown as iodine displace so chlorine more reactive than iodine
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
no change with sodium chloride but change brown with sodium iodide
bromine reacts with hydrogen to form hydrogen bromide describe colour change
from orange to colourless
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
colour is red because it formed ionization of h+
suggest why it is nessecary to have an open tube fitted in apparatus
to avoid gas pressure
for safety reasons this reaction should be carried out in fume cupboard explain why this is nessacry
chlorine is toxic gas
state why the teatcher does not add bromine solution to sodium bromide solution
because bromine cant replace itself
how is hydrogen chloride gas converted into hydrochloric acid
add to water
state why chlorine is sometimes added to water supplies
to purfy it as it is seterllised agent
suggest why the student does not need to add bromine solution to sodium bromide solution
bromine cant displace itsself
observation when add damp blue litmus paper[chlorine]
bleaches
observation when chlorine into a solution of pottasium iodide
brown
write a chemical reaction to show the formation of hydrogen chloride from hydrogen and chlorine
h2+cl2=2hcl
when water is added to this mixture and it is shaken a reaction occurs explain observations
bubbles of gas as in water h+ ions are formed so mg reacts to form hydrogen gas
colour of fluroine when g and aq and ions
yellow,colourless,colourless
colour of chlorinr when g and aq annd ions
green,yellow,colourless
colour of bromine when g and l and aq and ions
orange,brown,red or orange,colourless
colour of iodine when g,s,aq,ions
purple,dark grey,bown,colourless
colour of astatine when solid and ions
black,colorless
uses of fluorine
it is used in water supply and in toothpaste to prevent the decay of the enamel of the tooth
uses of chlorine
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
uses of iodine
it is used as antiseptic
general proprties of halogens
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
why reactivity decreases from up to doWN along this group why?
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
why hydrogen chloride is gas
because the molecules are bonded by weak inter molecular force
Is noble gas monoatomic or diatomic
Monoatomic
Is halogen monoatomoc or diaotomic
Diatomic
