Properties of Metals

Properties of Metals

Maria Vincent

-The Adroit 6

Maria Vincent

-The Adroit 6

PROPERTIES OF METALS

Physical Properties

Determining the Chemical Properties of Metals

Those features of metals which can be seen or felt.

Physical Properties

State of Existence

Conduct-ivity

Hardness

Lustre

Sonorosity

Malleabilty

Ductility

Melting/ Boiling

Allotropy

Tensile Strength

State of ExistenceSolids at room temperature

Exception: Mercury- Liquid

LustreHave a shiny surface (lustre)

when freshly cut.

ConductivityGood conductor of heat and

electricity.

Silver is the best conductor of heat and electricity.

HardnessUsually hard

Exception: Sodium, Potassium- soft

SonorisityThey are sonorous.

Malleability and Ductility

Metals are malleable and ductile.

Gold, silver and platinum are highly malleable and ductile.

Melting and Boiling Point

High melting and boiling point.

Exception: Gallium, cesium have low mp and bp.

AllotropyMetals do not exist in

allotropic forms.

Tensile StrengthHigh tensile strength (do not

break easily).

PROPERTIES OF METALS

Chemical Properties

Determining the Chemical Properties of MetalsDetermining the Chemical Properties of Metals

The tendency of metals to lose electrons from their valence shells.

CHEMICAL PROPERTIES OF METALSReaction of Metals with Oxygen

Metals reacting with Oxygen

What happens when a piece of magnesium ribbon is burnt

2Mg + O2 -----g2MgO(Grey colore

d)

(White powdery

substance)

Metals reacting with Oxygen

What happens when 1 gram of copper powder is heated?

2Cu + O2 -----g2CuO(Brow

n colore

d)

(BlackColored)

Metals reacting with Oxygen

What happens when sodium is left in the open?

4Na + O2 -----g2Na2O(Silvery-

white colored)

(GreyColored)

Metals reacting with Oxygen

We can have a generalized equation:

Metal + Oxygen ----g Metal Oxide

Nature of Metal Oxides

Oxides of metals like Na, K, Mg dissolve in water to form soluble hydroxides called alkalis.

These react with acids to form salt and water.

Na2O + H2O ----g 2NaOH

NaOH + HCl ----g NaCl + H2O

Nature of Metal Oxides

Oxides of metals like Ca, Fe react with water to form insoluble hydroxides called bases.

These react with acids to form salt and water.

CaO + H2O ----g Ca(OH)2

Ca(OH)2 + HCl ----g CaCl2 + H2O

Nature of Metal Oxides

Oxides of Al and Zn show basic as well as acidic behaviour- amphoteric oxides.

These react with acids and to form salt and water.

Al2O3 + 6HCl ----g 2AlCl3 + H2O

Al2O3 + 2NaOH ----g 2NaAlO2 + H2O

CHEMICAL PROPERTIES OF METALS

Reaction of Metals with Water

Metals reacting with Water

Highly reactive metals- Na, K- react violently in cold water and catch fire.

2Na + H2O -----g2NaOH + H2 + Heat

Metals reacting with Water

Calcium reacts with water less violently and magnesium reacts with water on heating.

+

Mg + 2H2O -----g Mg(OH)2 + H2

Metals reacting with Water

In general:

Metal + Water ----g Metal Hydroxide + Hydrogen

Metals reacting with WaterMetals of lower reactivity- Fe,

zn, Al- react with water only when steam is passed over heated metals.

3Fe + 4H2O -----g Fe3O4 + 4H2 (steam)

Metals reacting with Water

In general:

Metal + Steam ----g Metal Oxide + Hydrogen

CHEMICAL PROPERTIES OF METALS

Reaction of Metals with Acids

Metals reacting with Acids

Recall these reactions:

NaCl + H2

MgCl2 + H2

FeSO4 + H2

ZnSO4 + H2 Zn + H2SO4

Fe + H2SO4

Mg+ 2HCl

Na + HCl

-----g-----g-----g-----g

Metals reacting with Acids

Metals placed above hydrogen react with dilute acids to form salt and release hydrogen gas.

Metal + Acid ----g Salt+ Hydrogen

Metals reacting with Acids

Note: Metals do not evolve hydrogen gas when they react with dilute nitric acid. Nitric acid is a strong oxidizing agent and oxidizes the hydrogen evolved to water and it self gets reduced to an oxide of nitrogen.Zn+4HNO3 ----g Zn(NO)3 + 2H2O +

2NO2

CHEMICAL PROPERTIES OF METALSReaction of Metals with Solutions of Other Metallic Salts

Metals reacting with Other Metallic Salt Solutions

Metals placed higher in the reactivity series can displace the metal which occupies a lower position from its aqueous solution of its salt.

Metals reacting with Metallic Salt Solutions

Recall these reactions:

ZnSO4 + Fe

Al2(SO4)3 + 3Zn

Na2SO4 + Mg Na + MgSO4

2Al+ 3ZnSO4

Zn+ FeSO4

-----g

----g

-----g

Metals reacting with Other Metallic Salt Solutions

Metal + Other Metal’s Salt Solution ----g First Metal’s Salt Solution+ Metal from the Salt

Solution