chapters 14 and 15-the reactivity series including extraction and uses of metals Flashcards
What is the order of the reactivity series
potassium, sodium, lithium, calcium, magnesium, aluminium, (carbon), zinc, iron, (hydrogen), copper, silver, gold
what are the 4 reactions used to put metals in order of reactivity?
- displacement reactions involving metal oxides
- displacement reactions involving solutions salts
- metals with water
- metals with acid
describe which metals the reactivity series react with water or steam
- potassium to calcium react with cold water+ steam
- magnesium to iron react with steam
- copper to gold don’t react with water or steam
describe which metals react with acid
- potassium to calcium react explosively with acid, so strongly that they cannot be performed in a lab
- magnesium to iron react well with acids
- copper to gold do not react with acid as they are below hydrogen in the reactivity series
describe the rule concerning displacements in metals
a more reactive metal will displace a less reactive metal in its compound
what is a redox reaction?
a reaction involving oxidation and reduction
what is oxidation and reduction
oxidation is the gain of oxygen and loss of electrons, reduction is the loss of oxygen and gain of electrons (remember OILRIG)
what is an oxidising agent
a substance which oxidises something else (so is reduced)
what is a reducing agent
a substance which reduces something else (so is oxidised)
describe the rule concerning displacement reactions involving solutions of salts
a more reactive metal will displace a less reactive metal from a solution of one of its compounds
which metals in the reactivity series react with water (or steam)
metals above hydrogen
what are the products of a reaction with a metal (above hydrogen) + cold water
metal hydroxide ( metal OH) + hydrogen (H2)
what are the products of a reaction with a metal (above hydrogen) and steam
metal oxide (metal O) + hydrogen (H2)
how do group 1 metals in the reactivity series (potassium, sodium, lithium) react with cold water/ steam
react vigorously and they all fizz, float, move and dissolve- lithium does not ignite, sodium sometimes ignites with an orange flame and potassium ignites with a lilac flame
how do group 2 metals in the reactivity series (magnesium and calcium) react with cold water/steam
- less reactive than group 1
- calcium still reacts with cold water (see fig. 14.9 page 150)
- magnesium only reacts with steam ( see fig. 14.10 page 151)
how do zinc and iron react with cold water /steam
- react similarly to magnesium but are less reactive
- copper comes after these in the reactivity series and doesn’t react at all
which metals in the reactivity series react with acid
- metals above hydrogen react with dilute acids like Hal and H2SO4.
what are the products of a reaction with a metal+ acid
metal salt + hydrogen
how are most metals extracted
most metals are extracted from ores found in the earths crust. The most un-reactive metals (e.g gold) are often found uncombined as an element. Other metals are found as compounds from which the metal needs to be extracted
what does the method used to extract a metal depend on?
- Its position in the reactivity series
- cost of energy +reducing agent
describe how the different metals in the reactivity series are extracted
- metals above carbon in the reactivity series are extracted using electrolysis (this uses a lot of energy so it is expensive)
- metals below carbon in the reactivity series can be extracted using carbon- heated with carbon (this is cheaper than electrolysis)
- metals at the bottom of the reactivity series may be found native as elements
what does iron ore contain
iron (III) oxide
in the experiment with zinc or iron in the hydrogen experiment , why must you stop heating while the delivery tube is still under water?
because water will be sucked back into the hot tube, which often results in it cracking
what is an ore
a sample of rock which contains enough of a mineral for it to be worthwhile to extract the metal
what does native mean
exists naturally as an uncombined element
when does iron rust
in the presence of oxygen and water
what is rust made of
hydrated iron (III) oxide
how can we speed the process of rusting
using salt
how is the extraction of iron carried out
- in a blast furnace, it is heated with carbon and it is carbon monoxide which is the reducing agent
- since carbon is above iron in the reactivity series it will take the oxygen from iron (III) oxide- iron ore
what does exothermic mean
reactions which are exothermic give out heat
which metal rusts
ONLY iron- with other metals, we say that they corrode
briefly describe the experiment used to find the conditions needed for rusting
- 4 test tubes with different conditions, an iron nail is placed into each
- 1st test tube contains calcium chloride to remove water
- 2nd test tube contains boiled water to remove oxygen ( because when temperature increases, the solubility of gases decreases, so no oxygen can dissolve in the water), and oil is put ontop, in order to stop oxygen from entering the water once cooled
- 3rd test tube contains deionised water- without any additional compounds in it
- 4th test tube contains salt water
in which test tube does the iron nail rust best?
only the tubes containing oxygen and water
what can we coat iron with to protect from rusting (barrier method)
paint, oil, grease, plastic or electroplating (using electrolysis to coat the iron with a layer of another metal)
what is galvanising
coating iron with a layer of zinc
why doesn’t iron rust in galvanising, even when some of the zinc is scratched away?
zinc will react with any oxygen which comes close to the exposed iron because it is more reactive
where is galvanising used?
watering cans and buckets
what is sacrificial protection
- zinc, magnesium or aluminium blocks are attached to ships to prevent the iron/steel from rusting.
- the more reactive metal reacts (is oxidised) more readily than the iron
- the corrosion of the more reactive metal prevents the iron from rusting
- it is often used on large objects, like ships, which would be difficult / expensive to cover with a barrier
what is galvanising a combination of
the barrier and sacrificed protection method
what is an alloy
- a mixture of a metal and one or more other elements, usually other metals or carbon
- alloys are harder than pure metals because they contain different sized atoms which distort the regular arrangement go the ions and make it harder for the layers to slide over each other
what are the properties + uses of aluminium
- low density, strong (planes)
- good conductor of electricity, ductile (electricity cables)
- good conductor of heat, high melting point, resists corrosion (saucepans)
what are the properties + uses of copper
- very good conductor and ductile (electrical wires)
- unreactive and malleable (water pipes)
what are the properties + uses of low carbon (mild) steel
- strong and malleable but high density and rusts (nails, car bodies, ships and bridges)
what is low carbon steel
an alloy of iron and 0.25% carbon
what are the properties + uses of high carbon steel
harder and more resistant to wear but not as malleable and ductile- more brittle (cutting tools)
what is high carbon steel
an alloy of iron and about 1% carbon
what are the properties + uses of stainless steel
resistant to corrosion-doest rust-but expensive (kitchen sinks, cutlery and cooking utensils
what are the properties + uses of aluminium
- low density, strong (planes)
- good conductor of electricity, ductile (electricity cables)
- good conductor of heat, high melting point, resists corrosion (saucepans)
what are the properties + uses of copper
- very good conductor and ductile (electrical wires)
- unreactive and malleable (water pipes)
what are the properties + uses of low carbon (mild) steel
- strong and malleable but high density and rusts (nails, car bodies, ships and bridges)
what is low carbon steel
an alloy of iron and 0.25% carbon
what are the properties + uses of high carbon steel
harder and more resistant to wear but not as malleable and ductile- more brittle (cutting tools)
what is high carbon steel
an alloy of iron and about 1% carbon
what are the properties + uses of stainless steel
resistant to corrosion-doest rust-but expensive (kitchen sinks, cutlery and cooking utensils
what is stainless steel made of
iron, chromium, nickel
