Metals and the Reactivity Series Flashcards
Compare the general physical properties of metals and non-metals.
- metals have high melting/boiling points, non-metals have low
- metals are good electric conductors, non-metals are electric insulators
- metals are good thermal conductors, non-metals are thermal insulators
- metals are ductile/malleable, not non-metals
State the order of the reactivity series.
potassium
sodium
calcium
magnesium
aluminium
carbon
zinc
iron
tin
lead
hydrogen
copper
silver
gold
Where is hydrogen in the reactivity series?
below iron, above copper
Where is carbon in the reactivity series?
below aluminium, above zinc
Reaction of metals with water.
metal + water → metal hydroxide + hydrogen
Group I elements are ____ reactive than Group II.
more
Which elements are more reactive, group 1 or 2?
group 1
For metals, what does the group define about their reactivity?
the lower the group the more reactive
For metals, what does the mass of an element define about their reactivity?
heavier elements further down the group are more reactive
Mnemonic for reactivity series.
Please send cats, monkeys and zebras charging into hot countries,
Signed Greg
OR (para aluninhos do dicks - annuca):
please stop calling me a careless zebra, instead try learning how copper saves gold
Reaction of metals with dilute acids.
metal + acid → salt + hydrogen
Reaction of metals with oxygen.
metal + oxygen → metal oxide
What is aluminium used for and why?
- manufacture of aircraft: low density
- manufacture of overhead electrical cables: low density + good electrical conductivity
- food containers: resistance to corrosion
What is copper used for and why?
electrical wiring: good electrical conductivity and ductility
Describe the reaction of potassium with cold water.
- vigorous effervescence
- hydrogen gas released
- metal floats on water surface, gets smaller as it reacts
- after a short while the gas given off will ignite and a lilac-coloured flame seen
Describe the reaction of sodium with cold water.
- similar to potassium, but reaction is less vigorous so the hydrogen gas may not ignite
Describe the reaction of calcium with cold water.
- solid metal sinks
- bubbles produced on surface of the metal (much slower than K and Na)
- as metal disappears, solution becomes cloudy as calcium hydroxide is insoluble
Describe the reaction of magnesium with cold water/steam.
no reaction with cold water, but reacts with steam to form hydrogen and white powder (magnesium oxide)
The solid metal sinks, bubbles produce on the surface of the metal, as the metal disappears solution turns cloudy. What reaction is this?
calcium and water
Describe the reaction of magnesium with dilute HCl.
strong: bubbles form quickly on the surface, metal slowly disappears
Describe the reaction of zinc with dilute HCl.
bubbles slowly form
Describe the reaction of iron with dilute HCl.
very slow, must be powdered iron
Describe the reaction of copper/silver/gold with dilute HCl.
none
A metal reacts with dilute HCl. The reaction is slow and the metal must be powdered. What is the metal?
iron
A metal reacts with dilute HCl. The reaction is bubbles forming slowly. What is the metal?
zinc
Explain the apparent unreactivity of aluminium.
aluminium oxide forms quickly when aluminium is exposed to air, creating an oxide layer that creates a perfect barrier around the aluminium, preventing further metal reaction
How can displacement reactions be used to extract metals?
- carbon is more reactive than the metal, so it displaces the metal from its oxides
- produces pure metal and carbon dioxide
How can we extract metals less reactive than carbon?
mixing them with carbon (most likely as charcoal) and heating them to high temperatures
A _____ reactive metal displaces a _____ reactive metal.
more/less
What is a displacement reaction?
a more reactive element is taking the place of a less reactive element
State the conditions required for the rusting of iron and steel.
oxygen and water in the air
What is the chemical name for rust?
hydrated iron(III) oxide
Word equation for rusting
iron + water + oxygen → hydrated iron(III) oxide
Symbol equation for rusting
2Fe(s) + 2H2O(l) + O2(g) → Fe2O3·H2O(s)
State some common barrier methods.
- painting
- greasing
- coating with plastic
Which metal quickly forms an oxide layer, appearing unreactive?
aluminium
Describe how barrier methods prevent rusting.
by preventing oxygen or water from reaching the metal
What is a barrier method?
set of techniques to prevent corrosion by preventing oxygen and water coming into contact with the metal surface
What is zinc in galvanising an example of?
barrier method and sacrificial protection
Describe the use of zinc in galvanising.
iron/steel objects are completely coated in a thin layer of zinc, the zinc forms a barrier between the iron and oxygen in the atmosphere
What is sacrificial protection?
protecting a metal from corrosion by allowing another more reactive metal, to corrode instead
What is sacrificial protection often used for?
hulls of ships, as salt water accelerates rusting
Describe sacrificial protection.
- iron/steel placed in contact with a more reactive metal
- more reactive metals loses electrons more easily than iron
- presence of electrons prevents iron from oxidising
- while more reactive metals than iron remain in contact with the iron, it remains protected
uses of aluminium
- aluminium in the manufacture of aircraft because of its low density
- aluminium in the manufacture of overhead electrical cables because of its low density and good electrical conductivity
- aluminium in food containers because of its resistance to corrosion
use of copper
electrical wiring because of its good electrical conductivity and ductility
reactions of metals with water
potassium - most vigorous
sodium - vigorous
calcium- strong
magnesium - only reacts with steam
aluminium - no reaction
word equation for metal reaction with dilute acid
metal + acid → salt + hydrogen
word equation for metal reaction with water
metal + water → metal hydroxide + hydrogen
word equation for metal reaction with oxygen
metal + oxygen → metal oxide
metals reaction with dilute acid
potassium - explosive
sodium - violent
calcium - rapid with many bubbles
magnesium - rapid, steady bubbles
zinc - slow
iron - very slow
copper - nada
