air and water Flashcards
what is the percentage of each gas in air
78% nitrogen, 21% oxygen, 1% co2 and noble gas
what is the word equation of respiration
glucose + oxygen –> carbon dioxide + water + energy
what are the uses of oxygen
oxygen tent for hosp
cutting and welding metals
supply to diver and astronauts
why do we need nitrogen in the air
without it fuels wld burn too fast
how do you measure percentage of oxygen in air
connect a tube of hard glass to 2 gas syringe
put copper wire in the glass tube
1 syringe will contain 100cm3 of air
heat the glass tube
push the air from 1 syringe into the other, keep pushing the air from 1 syringe into the other
stop heating the tube after 3 mins and allow to cool
push all the gas into the first syringe and measure the volume of gas
repeat the steps until there’s no more change in volume - oxygen is used up
how do you separate gases from air
use fractional distillation
1. air is pumped into plant and filtered to remove dust particles
2. water vapour and carbon dioxide and pollutant are removed
-air is cooled until water forms. it passed over absorbent beads to trap co2
3.air is cooled until it becomes liquid
it is warmed slowly to allow gas to boil off separately
gases are put into tanks or cylinders under pressure
what is the order gases in air evaporated first?? JUST TELL ME WHICH GAS EVAPORATES FIRST WHEN WE SEPERATE THE AIR IN FRACTIONAL DISTILLATION 😭😭😭
CO2, NOBEL GASES, OXYGEN THEN NITROGEN WHY AM I IN CAPS STILL
what are some uses of nitrogen
inside food packaging to protect food from oxidisation in air
freezes liquid in cracked pipes before repairing them
freeze food in factories
store tissue samples in hosp
make ammonia
what are the uses of noble gases
argon light bulbs
neon for signs
helium for balloons
name some examples of fossil fuels
natural gas, coal, petroleum/crude oil
what are hydrocarbon
contain only carbon and hydrogen
what is in natural gas
methane
name some example of hydrocarbon
coal and petroleum
why do we burn fossil fuel
gives us energy for heating, transport and generating electricity
how is carbon monoxide get into air
when carbon compounds in fossil fuel burn in a limited supply of air like in engines
why is carbon monoxide harmful to the environment
poisonous
they react with haemoglobin in blood and prevents it from carrying oxygen ard body
when is sulfur dioxide formed
sulfur compound in fossil fuel burns
what harm does sulfur do
irritates eyes and throat
causes reparatory problems
produces acid rain
when is lead, the pollutant, formed
tetraethyl lead is added to petrol to help burn smoothly
when burnt it produces particles of other lead compounds
what harm does lead compounds do
harms kids brain
harms kidney and nervous system
what are the ways to reduce air pollution
waste gas is treated with slaked lime, this removes sulfur dioxide by reacting it with calcium sulphate
flue gas desulfurization
ban lead petrol
exhaust of new cars are fitted with catalytic converters
explain how the catalytic converters in car exhaust works
when petrol burns, oxides of nitrogen, co and unburnt hydrogen carbon are left- can cause cancer
catalytic converter absorb harmful gases on surface of the catalyst
catalyst speed up reaction
at the front, harmful compounds are reduces
at the other end, harmful compounds are oxidised
what are the equation is cataytic converter
2NO–> N2+o2
2CO+O2 –> 2co2
what are catalyst usually made of
transitional elements like platin
what are the adaptation for catalectic converter
coasted in honeycomb or ceramic beads to give large surface area for absorbing harmful gases
what is the meaning of corroded
broken down by reaction with something in the atmosphere
what is another word to describe rusting of iron
corrosion
what material/substance
- remove oxygen in liquid
- prevent air from coming in
- dries air
boiled water
oil
calcium chloride
what is the word and chemical equation of rusting
iron + oxygen +
water –> hydrated iron (III) oxide
4Fe + 3O + 4H2 –>2Fe2O3.2HO
how do we prevent rust
cover in iron to keep oxygen and water out use paint grease galvanising- coast in zinc let another metal corrode
how is steel coated with tin
by electroplating
how does letting another metal corrode prevent rusting
when rust, iron oxidises and loses electrons
Mg is more reactive so it wants to lose more electrons
what is another word for letting another metal corrode
sacrificial protection
where does water come from
river
underground
aquifer
how do you provide water supply
find a source remove as many solid particles -filter water through gravel/sand add smth to kill microbes store clean water in reservoir
how to test for water
turns white anhydrous copper II sulphate blue
turns blue cobalt II paper pink
how does a treatment plant works
water is pumped in and traps big particles
coagulant is added to make small particles stick tgt
air is blown through water in flotation tanks to make coagulated particles float and are skimmed off
water is passed through a bed of fine sand to filter it
choline is added to kill bacteria
fluoride added to prevent tooth decay
water is pumped into reservoirs
what is added to water to remove bad secant and smell
charcoal
how to prevent fertiliser fomr going into water and why shld we
can make babies ill
use special membrane but expensive
how can the colour change of chemical test for water be reversed
by heating
