C1 - the important bits / weaknesses Flashcards
explain why today’s atmosphere in different from the earth early atmosphere
less carbon dioxide
more oxygen
how were the oceans formed?
water vapour condensed
3 ways that human activity is changing the atmosphere
burning fossil fuels
livestock farming
deforestation
when is a natural activity that is changing the atmosphere?
volcanic activity
how could you investigate the proportion of oxygen in the atmosphere?
iron wool > iron oxide
name the three types of rocks
sedimentary
metamorphic
igneous
what type of rock is marble and how is it formed?
metamorphic
heat and pressure
what type of rock is chalk?
sedimentary
what is the difference in the way the crystals of extrusive and intrusive rocks form
extrusive - quickly
intrusive - slowly
name three building materials made from limestone
cement
concrete
glass
sand
what is thermal decomposition?
the decomposition of carbonated to produce Carbon dioxide
write down the symbol equation showing the thermal decomposition of limestone
CaCO(3) > CaO + Co(2)
how could you test for Carbon dioxide in a thermal decomposition reaction?
it would turn the limewater cloudy/milky
write down the symbol equation for the thermal decomposition reaction of zinc carbonate
ZnCO(3) > ZnO + CO(2)
what product can be made by adding water to calcium oxide and why is it useful?
calcium hydroxide (limewater) which can be used to test for Carbon dioxide
are atoms lost/made in a reaction or just rearranged?
rearranged because atoms aren’t lost or made in a chemical reaction
what is a precipitate?
the insoluble solid that is formed when two solutions react
if you carry out a reaction in a sealed container, what would you notice about the mass of the reactants and products?
there would be no change because no reactants or pedicure can’t escape
what does a number in front of a formula apply to?
the amount of atoms that specific element has
what is the state symbol for “dissolved in water”
aq
name the two main gases that make up the earths atmosphere today
nitrogen, oxygen, Carbon dioxide and other gases
do acids have a pH greater or less than 7?
less
name the acid produced by the stomach
hydrochloric acid
how do indigestion tablets work?
they neutralise the excess acid in the stomach
what do you get when you react an acid with a metal oxide?
salt and water (maybe Carbon dioxide)
is the anode positive or negative?
positive
are anions attracted to the anode?
yes
how would you test for hydrogen gas?
the gas would make a “squeaky pop” sound when lighted
name a product of the electrolysis of salt
water
when water undergoes electrolysis, what gases are given off?
hydrogen and oxygen
what is a metal ore?
two or more elements combined to form a compound which has enough of a metal to make it wort. extracting
what is the difference between oxidation and reeducation?
oxidation is the gaining of oxygen, reduction is the removal of oxygen
what are the two ways which metals are often extracted from their ores?
electrolysis and heating with Carbon
what is bauxite?
the main ore of aluminium
metals are used for car bodies, saucepan based and electrical wires. for each of these uses give one reason why metals are appropriate
flexible/strong
conducts heat
conducts electricity
why are metals high in the reactivity series more likely to corrode?
because they’re more likely to react
why are alloys stronger than pure metals?
pure metals have all the same sized atoms in a regular arrangement so the layers of metals can easily slide over each other, however, alloys have different sizes atoms because there is more than one element so it STOPS the layers of metals from sliding over eachother / move
give three reasons why it is good to recycle metals
save resources
saves money
uses less energy
what does crude oil consist of and what does fractional distillation do to crude oil?
a mixture of different sized hydrocarbon molecules
fractional distillations splits up the crude oil into more useful separate fractions / fuels
what’s so clever about smart alloys?
they have shape memory so when heated they can convert back to there original shape - E.g nitinol (nickel and titanium)
what is produced during complete combustion of hydrocarbons?
Carbon dioxide and oxygen and energy
what are four things you might want to consider when deciding on the best fuel to use
ease of ignition
energy value
ash and smoke
storage and tansport
explain how incomplete combustion can be harmful to humans
it can kill lots of people because carbon monoxide is a product which is a colourless, odourless and very toxic (poisonous) gas
what problems are associated with acid rain?
cause lakes to become acidic and many places still and animals die as a result
kills trees and damages limestone buildings
ruins stone statues
list three ways of reducing acid rain
reduce usage of fossil fuels
cats being fitted with catalytic converters to clean up their exhaust gases
power stations have acid gas scrubbers to take harmful gases out before they release their fumes into the atmosphere
list two ways in which human activity is increasing Carbon dioxide levels
burning fossil fuels
deforestation
what are biofuels?
fuels that are made my microorganisms that are renewable and remove Carbon dioxide from the air
what are the reactants and products in fuel cells?
fuel + oxygen = energy
what is a fuel cell?
an electrical cell that’s supplied with a fuel and oxygen and users energy from the reaction between them to generate electricity
list one advantage and one disadvantage of fuel cells
advantage = much more efficient than power stations or batteries at producing energy
electricity is generated directly from the reaction
disadvantage = it won’t end the use of fossil fuels because it’s very explosive so it is difficult to store safety
how would you if it was an alkene/alkane or has single/double bonds?
add bromine water
- remains the colour of bromine water = alkane
- declolourise/turns clear = alkene
what are monomers?
small molecules e.g. alkenes
what are polymers?
long chains of molecules that are lots of joined up monomers (small molecules)
how is igneous rock formed?
magma cooling and solidifying
why do extrusive igneous rocks have different sized crystals than intrusive igneous rocks?
they cool quicker
extrusive rocks have big/small sized crystals
small
intrusive igneous rocks have big/small sized crystals
big
give two examples of sedimentary rocks
limestone and chalk
give an example of a metamorphic rock
marble
give an example of an igneous rock
granite
what can be found in sedimentary rocks?
fossils
why are fossils never found in igneous rocks?
they are exposed to too high temperatures
what is the chemical name for chalk, marble and limestone?
calcium carbonate
give an advantage of quarrying limestone
provides jobs - better economy
limestone gives people what they want - roads etc
give an disadvantage of quarrying limestone
noisy in remote areas
pollution from transporting limestone
detritus landscape
what can you make from calcium carbonate?
cement concrete glass buildings statues
what is thermal decomposition?
the breaking down of a compound into two other elements using electrical heat
what happens to limewater when Carbon dioxide is bubbles through it?
becomes cloudy/turns milky
what happens to the mass of react bars and the mass of products during a chemical reaction?
stays the same
why do farmers add calcium yo their soil?
neutralises the acid in the soil
why does your stomach produce hydrochloric acid?
to break down food
kill bacteria
what type of chemical do we use to neutralise acids?
bases - alkalis
what is the reaction called when an acid becomes neutral by using an alkali?
neutralisation
what colour and pH is neutral when using universal indicator?
Green
pH 7
a hydrochloric acid produces what salts?
chloride
a nitric acid produces what salts?
nitrate
a sulfuric acid produces what salts?
sulfate
what does electrolysis mean?
the breaking down of a compound using electricity
when you pass electricity through hydrochloric acid, what two things are made?
hydrogen and chlorine
describe the chemical test for chlorine
blue/damp litmus paper bleached
describe the chemical test for hydrogen
when lite makes a squeaky pop sound
describe the chemical test for oxygen
relight a glowing splint
where are most ores found?
earths crust
how are most unreactive metals found?
in their native state - uncombined
give the name of a metal that is extracted by heating with Carbon
zinc
tin
iron
Nickel
why are different metals extracted in different ways?
some are more reactive than others
what does oxidation mean?
adding of oxygen > oxides
what does reduction mean?
removal of oxygen
what reaction is it when you extract metals from their ores?
oxidation
what does corrosion mean?
when the metal corrodes / reacts with oxygen in the air
re ire the order of the reactivity series, starting with the most reactive
potassium sodium calcium magnesium aluminium Carbon zin iron tin lead
metals are hard to oxidise or corrode when they are found where in the reactivity series?
bottom - least reactive
3 advantages of recycling
less energy
less money
less resources
what is a disadvantage of recycling?
can be expensive
give a use for aluminium and why it is used for it
aircrafts
low density
give a use for gold and why it is used for it
jewellery - can be shaped / doesn’t corrode
give a use for steel and why it is used for it
electrical pipes > good conductor
give 2 reason why iron is made into an alloy
it is harder so it has a more stable structure
what is an alloy?
when 2 or more elements combine/react
sea water is sodium chloride solution, when decomposed one product is a toxic gas, which is it?
chlorine
give a safety precaution that should be taken when collecting toxic gas
gas masks must be worn so that you don’t breathe it in
what are the three conditions for cracking?
high temperature
catalyst
long chain alkane
why is cracking useful?
shorter chains have a wider variety of uses
