Studied by 5 people
state what most metals are known as
transition metals
state the properties of transition metals
high melting/boiling point
high density
they form coloured compounds
catalysts of metals and their compounds
state what the oxidation of iron causes
corrosion
state the definition of corrosion
the gradual destruction of metal
due to chemical reactions between metals, oxygen and water
explain how the exclusion of oxygen can prevent iron rusting
rusting is the reaction of oxygen, water and metal together
to form iron oxide
without oxygen, this reaction cannot take place
explain how the exclusion of water can prevent iron rusting
rusting is the reaction of oxygen, water and metal together
to form iron oxide
without water, this reaction cannot take place
explain how sacrificial protection can prevent iron rusting
when iron is galvanised with a metal of a higher reactivity
the iron is protected from water and oxygen by a physical barrier
although reactions will take place with the galvanised metal, oxygen and water
the iron will remain unreacted
state what electroplating is
process where
the surface of one metal
is coated with the layer
of a different metal
explain how electroplating can be used to improve the appearance of metal objects
electroplating allows a metal object to be coated in a layer of another metal
this coating could improve the appearance of the metal object
e.g. silver plating cutlery and jewellery
explain how electroplating can be used to improve the resistance to corrosion of metal objects
electroplating allows a metal object to be coated in a layer of another metal
this coating is usually a metal with higher reactivity than the metal object
this mean the metal coating will react with oxygen and water and corrode
meaning the metal object is physically protected from the oxygen and water
state what a metal alloy is
where metals are physically mixed together
but not chemically combined
explain why converting metal into alloys increases the strength of the product
alloys often have properties that differ to the pure metal
alloys contain atoms of different sizes that disrupt the regular arrangement of atoms
this makes it harder for the layers of metal atoms to slide over each other
making the alloy harder than the pure metal
thus making it stronger
explain why iron is alloyed with other metals to produce alloy steels
cast iron from a furnace is 96% iron
with carbon, phosphorus, silicon and sulfur impurities
cast iron is too brittle for many common uses
so it is alloyed to make steel by removing some of the impurities
where it can then be used for actions such as construction, transport and manufacturing
explain how the uses of aluminium as foil is related to its properties
used in domestic food wrapping/storing food
as it has a low reactivity
and is very malleable
state what the magnalium alloy is made of
magnesium
aluminium
explain how the uses of magnalium in aircraft parts is related to its properties
magnalium is low density
and corrosion resistant
meaning it is a safe material to use in aircrafts
explain how the use of copper in electrical wirings is related to its properties
copper is corrosion resistant
and an electrical conductor
making it a safe material to use in the wirings
state what brass is made of
copper
zinc
explain how the use of brass in pins for electrical plugs is related to its properties
brass is stronger than copper
and is also an electrical conductor
making it a good material to use in the pins
state what jewellery gold is made of
gold
copper
explain how the use of jewellery gold in in jewellery is related to its properties
the gold alloy allows the jewellery to stay strong
whilst still remaining shiny
and corrosion resistant
state the equation to find concentration in mol/dm³
concentration (mol/dm³) = no. of moles (mol) / volume (dm³)
state the equation to convert concentration in mol/dm³ to g/dm³
g/dm³ = mol/dm³ x Mr
state the equation to convert concentration in g/dm³ to mol/dm³
mol/dm³ = g/dm³ / Mr
state the method of how to carry out an acid-alkali titration
use pipette and pipette filler to place 25cm³ of NaOH solution into the conical flask
place the conical flask on a white tile so the tip of the burette is inside the flask
add a few drops of suitable indicator to the conical flask
perform a rough titration by taking an initial burette reading, while swirling the flask
quickly close the tap when a sharp colour change occurs and record the final volume at eye level
repeat the titration with a fresh flask of NaOH solution
at the rough end volume, add the solution from the burette one drop at a time until the indicator just changes colour
record the volume to the nearest 0.5cm³
repeat until 2 concordant results are achieved
explain how to use titration results to carry out simple calculations
write out the balanced reaction of the neutralisation reaction
calculate the moles of the known solution given the volume and concentration
use the equation to deduce the moles of the unknown solution
use the moles and the volume of the unknown solution to calculate the concentration
state the equation to find percentage yield
% yield = (actual yield / theoretical yield) x 100
state what actual yield is
the yield of a reaction
that is usually less than the calculated theoretical yield
state what causes the actual yield of a reaction to be less than the theoretical yield
incomplete reactions
practical losses during the experiment
competing, unwanted reaction
state what atom economy is
studies the amount of reactants that get turned into useful products
it’s used to analyse the efficiency of reactions
state the equation to find atom economy
atom economy = (Mr of desired products / Mr of all reactants) x 100
explain why a particular pathway in a reaction is chosen to produce a specified product using atom economy
reactions that have low atom economies use up a lot of resources
and produce excess waste material
which needs to be disposed of
making it an expensive procedure
these reactions are unsustainable as they aren’t economically attractive
explain why a particular pathway in a reaction is chosen to produce a specified product using yield
high yield rates are desirable attributes of chemical reactions
as they produce less waste products
therefore improving the efficiency of the reaction
making the reaction more economically-attractive
explain why a particular pathway in a reaction is chosen to produce a specified product using equilibrium position
Note 
Flashcard (135)