metals Flashcards
metallic structure
a lattice of positive metal ions
a sea of delocalised electrons
metallic bonding
-the electrostatic attraction between the positive metal ions and the negative delocalised electrons
very strong attraction
metallic properties
-high boiling points- because metallic bonding is very strong so requires lots of energy to break
-conduct electricity- delocalised electrons are free to move through the lattice
-metals are malleable- layers of metal ions can slide over eachother
metal carbonate reaction
the thermally decompose to form metal oxide + carbon dioxide
thermal decompostition of copper carbonate
-coper carbonate (green solid)> copper oxide (black solid) + carbon dioxide (colourless gas)
downward delivary
carbon dioxide is denser than air so it sinks to the bottom of a tube until collected
metal + water reaction
metal + water> metal hydroxide + hydrogen
observation of metal + water reaction
effervescence- hydrogen gas produced
solid disapears- used up in reaction
describe metal reactions with reactivity trends
metals that are less reactive that magnesium are so slow you cannot tell anything is happening
group one metal + water reactions
.they react violently to form metal hydroxide + hydrogen
observations of group one metal
.solid floats at start as it is less dense than water
-effervescence- hydrogen gas is produced
solid moves- effervescence propels solid around surface of water during reaction
solid disappears, used up in reaction
what happens when universal indicator is used afger reaction
turns dark blue,
alkali is present (metal hydroxide)
lithium reaction with water
fast reaction
vigirous
sodium reaction with water
.faster than lithium
.sodium melts
potassium reaction with water
fastest reaction
K melts
liliac flame produced
metal + steam reaction
forms metal oxide + hydrogen
how to carry out a metal + steam reaction
1.)metal magnesium is placed into a metal tube with wet wool
2.) wet wool is heated producing steam
3.) steam reacts with magnesium to form magnesium oxide in tube
4.) hydrogen is burnt to safely destroy it
metal + acid
salt + hydrogen
eg magnesium+ sulphuric acid > magnesium sulphate + hydrogen
observations in acid + metal reaction
metal disappears- used up in reaction
fizzing- hydrogen in produced
why can we not use metals that are less reactive than hydrogen e.g. gold or copper
less reactive, so cannot displace Hydrogen from the acid
why can we not us Li Na and K
reaction with acids is too violent
explain the trend in reactivity series and acid reaction
more reactive a metal is, faster it will react with an acid
chemical test for hydrogen
lit splint > squeaky pop
combustion of hydrogen cause test tube to resonate
which salts are always dissolvable in water
sodium- Na+
potassium- K+
Ammonium- NH4+
Nitrate- NO3-
ores
metals are found in the earths crust as compounds with oxygen and sulfur as over time these metals have reacted
natives
gold and silver are too unreactive to have combined with oxygen and sulphur
they are found chemically unchanged
metal extractions to chemically extract metals from compounds
using electricity- metals more reactive than carbon cannot be displaced by carbon.
electricity is used instead eg aluminium
carbon extraction
metals less reactive that carbon can be displaced by carbon
eg copper can be displaced from its ore using carbon
rusting
chemical process in which iron is oxidised to form rust
chemical name for rust
hydrated iron(III) oxide
how does rusting work
1.) iron is oxidised (gains oxygen) to form iron(III) oxide. iron has also lost electrons
2.) iron(III) oxide is hydrated by water
amount of water varies
rusting can be prevented by
using barriers
sacrificial protection
how does barriers work
.coating iron in paint, oil grease or plastic prevents iron coming into contact with oxygen and water
oil - for moving parts (bike chain)
paint- more stationary objects
sacrificial protection
attach a block of a more reactive metal to the iron
this sisplaces iron from rust
eg magnesium+ Iron(III) oxide > magnesium oxide + Iron
galvanising
coating iron in zinc
.coating prevents O2 and H20 from coming into contact with iron
and zinc is more reactive so acts as a sacrificial protection too
