Wednesday 27th July Reactions of metals

Metals and Non-metals metal Non-metal Hard to say! H Li Na K Rb Cs Fr Be Sc Ti Mg V Cr Mn Fe Co Ni Cu Zn Ga Ge Se Br Ca Kr Y Zr Nb Mo Tc Ru Pd Ag Cd In Sn Sb Sr Te Rh Ba Hf Ta W Re Os Ir Au Hg Tl Pb Bi Po La At Pt Ra Rf Db Sg Bh Hs Mt ? Ac Al P N O S Cl F Ne Ar Rn I Si Xe He B C As Mg Mg P P S S Fe Fe Cu Cu Sb Sb I I

Metals and Non-metals Metals and non-metals have very different physical properties. Because of this the position of metals and non-metals show a pattern in the Periodic Table: Metals are on the left and centre. Non-metals are mostly on the right In between are metalloids – these are like metals in some ways and like non-metals in others.

Properties of metals:

Properties of non-metals Except graphite

Reactions of metal with oxygen

Reactions with oxygen Most metals react with oxygen (tarnish) – but they may do so in very different ways. Some react faster than others and some may not react at all. Some metals burn better than others When a metal reacts with oxygen it forms a metal oxide.

Demo: reactions with oxygen Below are some observations. Magnesium The ribbon burned with a dazzling white flame giving grey-white smoke and ash. Copper The copper turnings went through reds and oranges and then slowly got a permanent coating of black. Iron The iron filings glowed red and sparkled leaving a brown-black looking solid.

Reaction with oxygen - equations Metal + oxygen  metal oxide  oxygen + magnesium magnesium oxide 2Mg + O2  2MgO  oxygen + copper 2Cu + O2  2CuO  + iron 4Fe + 3O2  2Fe2O3

Put these three metals in order of reactivity with oxygen - magnesium, copper, iron. 2. 3.

Reactions of metal with water

Observing reactions with water Some metals (like lead and copper) react only slowly with water – they used to be used for pipes. Other metals react quickly with water and can be dangerous. Modern pipes – not lead but copper or plastic Metal + water  Metal hydroxide + hydrogen ( less reactive metal + steam  Metal oxide + hydrogen)

Reactivity series Potassium Sodium Calcium Magnesium Aluminium Zinc Iron Lead Copper Silver Gold

What will happen? K + Cu SO4

Copy and complete Potassium + iron sulphate  Aluminium + silver nitrate  Copper + Zinc chloride  Iron + Sodium chloride  Magnesium + iron Sulphate  Potassium + aluminium chloride  Calcium + lead nitrate  Sodium + calcium chloride  Iron + lead sulphate  Aluminium + iron oxide 

The Thermit reaction magnesium fuse The thermit reaction takes place between aluminium and iron oxide. It is so exothermic that molten iron is produced and the reaction is used to repair broken railway tracks. iron oxide + aluminium powder K Na Ca Mg Al Zn Fe Cu Ag Au +  Aluminium Oxide Aluminium Iron Oxide + Iron more reactive less reactive Aluminium wins the competition. Iron is displaced and melts at the high temperatures produced.

Here is a photo of the thermit reaction being carried out in a laboratory. magnesium fuse iron oxide + aluminium powder

Extension How many words can you make out of the word: DISPLACEMENT