Metals & Metal Compounds D. Crowley, 2007

Metals & Metal Compounds Wednesday, April 19, 2017 Metals & Metal Compounds To be able to predict the reactions between metals and metal compounds

Reactivity Series What can you say about the reactivity of metals? Some metals are more reactive than others (remember gold in water is fine, sodium in water is not)! We can order the reactivity of the metals, from most reactive to least This is the reactivity series!

Reactivity Series Look at the reactivity series – see if you can come up with a way to remember it… Potassium Sodium Calcium Magnesium Aluminium Zinc Iron Lead (Hydrogen) Copper Silver Gold Platinum Very reactive Fairly reactive Not very reactive Not at all reactive Metals below hydrogen do not react with water or acid – they do not easily tarnish!

Displacement Some metals are more reactive than others A displacement reaction is where one metal kicks another out A more reactive element reacts with a compound and pushes out a less reactive “rival” element

zinc + copper oxide → zinc oxide + copper Displacement E.g. zinc is more reactive than copper – it will react with the copper oxide when heated The zinc will displace the copper, leaving copper on its own and forming zinc oxide… zinc + copper oxide → zinc oxide + copper Zn + CuO → ZnO + Cu

Displacement So the more reactive zinc has pushed the copper out, and formed zinc oxide It’s a bit like a little guy going out with a girl. Everything is fine, until a bigger guy comes along and pushes the little guy away The big guy gets the girl, the little guy goes home alone… Try the Chem Wars: - http://sycd.co.uk/chemwars In our example, zinc is the big guy, copper the little guy, and the oxide is the girl!

Experiment To prove the reactivity series, you are going to react a metal and a metal compound together Firstly you will need a copy of the results sheet…

Results Sheet X Copper sulphate Iron sulphate Lead nitrate Magnesium sulphate Total reactions Copper X Iron Lead Magnesium Total

Experiment 1 Get a test tube rack, and 3 test tubes Fill each test tube up ½ way with copper sulphate Add a small piece of iron to one Add a small piece of lead to the second Add a small piece of magnesium to the third Has there been a reaction? Look for colour changes on the surface of the metal; colour changes in the solution; bubbles of gas given off; a temperature change If there was a reaction but a tick in your table; if not put a cross

Experiment 2 Get a test tube rack, and 3 test tubes Fill each test tube up ½ way with iron sulphate Add a small piece of copper to one Add a small piece of lead to the second Add a small piece of magnesium to the third Has there been a reaction? Look for colour changes on the surface of the metal; colour changes in the solution; bubbles of gas given off; a temperature change If there was a reaction but a tick in your table; if not put a cross

Experiment 3 Get a test tube rack, and 3 test tubes Fill each test tube up ½ way with lead nitrate Add a small piece of copper to one Add a small piece of iron to the second Add a small piece of magnesium to the third Has there been a reaction? Look for colour changes on the surface of the metal; colour changes in the solution; bubbles of gas given off; a temperature change If there was a reaction but a tick in your table; if not put a cross

Experiment 4 Get a test tube rack, and 3 test tubes Fill each test tube up ½ way with magnesium sulphate Add a small piece of copper to one Add a small piece of iron to the second Add a small piece of lead to the third Has there been a reaction? Look for colour changes on the surface of the metal; colour changes in the solution; bubbles of gas given off; a temperature change If there was a reaction but a tick in your table; if not put a cross

Reactions So some metals are more reactive than others – of ours the reactivity series of the metals was: - Magnesium (3 displacements) Iron (2 displacements) Lead (1 displacement) Copper (0 displacements) Magnesium displaces the copper: magnesium + copper oxide → magnesium oxide + copper Iron displaces the copper: iron + copper oxide → iron oxide + copper

Equations - Magnesium The equations for the magnesium was: - copper sulphate + magnesium → magnesium sulphate + copper (REACTION) iron sulphate + magnesium → magnesium sulphate + iron lead nitrate + magnesium → magnesium nitrate + lead

Equations - Iron The equations for the lead were: - copper sulphate + iron → iron sulphate + copper (REACTION) lead nitrate + iron → iron nitrate + lead magnesium sulphate + iron → magnesium sulphate + iron (NO REACTION)

Equations - Lead The equations for the lead were: - copper sulphate + lead → lead sulphate + copper (REACTION) iron sulphate + lead → iron sulphate + lead (NO REACTION) magnesium sulphate + lead → magnesium sulphate + lead

Equations - Copper The equations for the lead were: - iron sulphate + copper → iron sulphate + copper (NO REACTION) lead nitrate + copper → lead nitrate + copper magnesium sulphate + copper → magnesium sulphate + copper

Equations - Magnesium The equations for the magnesium was: - copper sulphate + magnesium → magnesium sulphate + copper CuSO4 + Mg → MgSO4 + Cu (REACTION) iron sulphate + magnesium → magnesium sulphate + iron FeSO4 + Mg → MgSO4 + Fe (REACTION) lead nitrate + magnesium → magnesium nitrate + lead Pb(NO3)2 + Mg → Mg(NO3)2 + Pb (REACTION)

Equations - Iron The equations for the lead were: - copper sulphate + iron → iron sulphate + copper CuSO4 + Fe → FeSO4 + Cu (REACTION) lead nitrate + iron → iron nitrate + lead Pb(NO3)2 + Fe → Fe(NO3)2 + Pb (REACTION) magnesium sulphate + iron → magnesium sulphate + iron MgSO4 + Fe → MgSO4 + Fe (NO REACTION)

Equations - Lead The equations for the lead were: - copper sulphate + lead → lead sulphate + copper CuSO4 + Pb → PbSO4 + Cu (REACTION) iron sulphate + lead → iron sulphate + lead FeSO4 + Pb → FeSO4 + Pb (NO REACTION) magnesium sulphate + lead → magnesium sulphate + lead MgSO4 + Pb → MgSO4 + Pb (NO REACTION)

Equations - Copper The equations for the lead were: - iron sulphate + copper → iron sulphate + copper FeSO4 + Cu → FeSO4 + Cu (NO REACTION) lead nitrate + copper → lead nitrate + copper Pb(NO3)2 + Cu → FeSO4 + Cu (NO REACTION) magnesium sulphate + copper → magnesium sulphate + copper MgSO4 + Cu → MgSO4 + Cu (NO REACTION)