chem - chap 12: reactivity series

potassium ( cold water )

reacts very violently → forms potassium hydroxide and hydrogen gas

eqn; 2K(s) + 2H2O(l) → H2(g)

sodium ( cold water )

reacts violently → forms sodium hydroxide and hydrogen gas

eqn ; 2Na(s) + 2H2O(l) →2NaOH(aq) + H2 g

calcium - cold water

reacts readily → forms calcium hydroxide + hydrogen gas

eqn: Ca(s) + 2H2O → 2Ca(OH)2(aq) + H2(g)

magnesium - cold water

reacts very slowly → forms magnesium hydroxide + hydrogen gas

eqn; Mg(s) + H2O (l) → Mg(OH)2(s) + H2(g)

Zinc with Cold Water

does not react with cold water.

Iron with Cold Water

Iron does not react with cold water.

HOWEVER may react slowly w/ water in presence in air= rusting

Lead, Copper, and Silver with Cold Water

no reaction

Magnesium - steam

reacts violently

Word Equation:
Magnesium + Steam → Magnesium oxide + Hydrogen

Chemical Equation:
Mg + H₂O (steam) → MgO + H₂↑

potassium,sodium,calcium - steam

react explosively

shld NOT be carried in sch lab

zinc - steam

reacts readily

Word Equation:
Zinc + Steam → Zinc oxide + Hydrogen

Chemical Equation:
Zn(s) + H₂O(g) (steam) → ZnO(s) + H₂(g)↑

Iron (Fe) - steam

reacts slowly

must be constantly heated fir reaction to process

Word Equation:
Iron + Steam → Iron(II,III) oxide + Hydrogen

Chemical Equation:
3Fe(s) + 4H₂O(g) (steam) → Fe₃O₄(s) + 4H₂(g)↑

lead,copper,silver - steam

no reaction

reaction of metals w/ dilute acid e.g. HCL,H2SO4,HNO3

hydrochloride (HCL) - metal+ dilute hydrochloric acid → metal chloride + hydrogen

sulfuric (H2SO4) - metal + dilute sulfuric acid → metal sulfate + hydrogen

nitric acid → metal + dilute nitric acid → metal nitrate + hydrogen

Potassium + Hydrochloric Acid

reacts explosively – not done in labs

Word Equation: Potassium + Hydrochloric acid → Potassium chloride + Hydrogen

Chemical Equation: 2K(s) + 2HCl(aq) → 2KCl(aq) + H₂(g)↑

Sodium + Hydrochloric Acid

reacts explosively - shld nt be carried in lab

Word Equation: Sodium + Hydrochloric acid → Sodium chloride + Hydrogen

Chemical Equation: 2Na(s) + 2HCl(aq) → 2NaCl(aq) + H₂(g)↑

Calcium + Hydrochloric Acid

reacts violently

Word Equation: Calcium + Hydrochloric acid → Calcium chloride + Hydrogen

Chemical Equation: Ca(s) + 2HCl(aq) → CaCl₂(aq) + H₂(g)↑

Magnesium + Acid

reacts rapidly

Word Equation: Magnesium + Hydrochloric acid → Magnesium chloride + Hydrogen

Chemical Equation: Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)↑

With Sulfuric Acid: Mg(s) + H₂SO₄(aq) → MgSO₄(aq) + H₂(g)↑

Zinc + Dilute Acids

moderately fast

Word Equation (with HCl): Zinc + Hydrochloric acid → Zinc chloride + Hydrogen

Chemical Equation: Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)↑

With Sulfuric Acid: Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂(g)↑

Iron + Dilute Acid

reacts slowly

Word Equation (with HCl): Iron + Hydrochloric acid → Iron(II) chloride + Hydrogen

Chemical Equation: Fe(s) + 2HCl(aq) → FeCl₂(aq) + H₂(g)↑

With Sulfuric Acid: Fe(s) + H₂SO₄(aq) → FeSO₄(aq) + H₂(g)↑

Lead + Dilute Acids

reacts very slowly

Word Equation (with HCl): Lead + Hydrochloric acid → Lead(II) chloride + Hydrogen

Chemical Equation: Pb + 2HCl → PbCl₂ + H₂

With Sulfuric Acid: Pb + H₂SO₄ → PbSO₄ + H₂↑

copper + silver

no reaction

a more reactive metal will displace a less reactive metal from its salt solution

eg zinc + copper sulfate → zinc sulfate + copper

copper (II) (blue) colour observation

copper-iron; no reaction

copper-mg; no reaction

copper-zn; no reaction

iron colour observation

fe-copper; blue → green

fe-mg; no reaction

fe-zn; no reaction

magnesium colour observation

mg-copper; blue→colourless

mg-fe; pale green → colourless, dark grey solid produced

mg-zn; solution remains colourless, grey solid produced

zinc colour observation

zn-cu; blue→ colourless, reddish brown solid formed

zn-fe; pale green→ colourless, dark grey solid produced

zn-mg; no reaction

most reactive to least reactive

magnesium,zinc,iron,copper

electrolysis → (Ka.Na,Ca,Mg) → breakdown

• reactive metal high up in the reactivity series

• their compounds are very difficult to break down

• using electricity to decompose the molten metal compound (ore)

ore

: mixture of huge volumes of rack & earth mixed w/ metals ( often the oxides, sulfides, chlorides / carbonate)

e.g. azurite, a copper ore, is a mixture of copper(II) carbonate and copper(II) hydroxide. haematite, an iron ore, is a mixture of iron(II)oxides + silicon dioxide

carbon

a substance, more reactive than (Zn,Fe,lead,Cu,Silver), that can be used to displace metals from their oxides to form metals

zn,fe,lead,cu,silver → reduction w/ carbon, less reactive metals

the more reactive metal is → less likely it is to reduce its oxide of the metal to the metal

mixture of copper(II) oxide and carbon is heated, copper(II) oxide is reduce to copper and carbon is oxidised to CO e.g. CuO(s) + C(s)→ Cu (s) + CO2(g)

if experiment repeated using mgo, no reaction takes place