chapter 8 Flashcards
why does reactivity in halogens decrease going down the group
The atomic radius gets bigger and so does electron shielding so it is more difficult for the halogens to gain and keep the electron
what is disproportion
when a element is both oxidised and reduced
what are the benefits of using chlorine in water
kills bacteria
what are the disadvantages of using chlorine
can react with organic hydrocarbons(free radical substitution) to form chlorinated hydrocarbons that could be cancerous
describe the carbonate test
add dilute nitric acid to the solid or solution
if bubbles could be a carbonate
bubble through limewater and if the limewater turns cloudy it is a carbonate as it is CO2
describe the sulfate test
Add barium nitrate
white precipitate will be formed that is BaSO4
Describe a test for halides
Add silver nitrate to the solution if a white precipitate is found it could be chlorine if cream it could be bromine if yellow could be Iodine to check whether it is Bromine or CL add ammonia chlorine will dissolve
what is the correct sequence for the anion tests
carbonate, sulphate, halide
what is the test for cations (NH4+)
ADD sodium hydroxide whilst heating solution , ammonia gas is produced, it will turn indicator paper blue and smell
what are the benefits of using chlorine to treat water
kills bacteria
what are the disadvantages to adding chlorine to drinking water
it can be highly toxic and cause respiration issues if concentrated
