AQA C1 2.1 Limestone, Carbonates, Decomposition, cement & Matals.

Rock mainly contains calcium Carbonate. (CaCo3)

Cement ---> Powdered Limestone + (roast )Powdered Clay  

Concrete ---> Cement + Water + Crushed Rock

Reinforced Concrete ---> Cement + water + Crushed Rock + Steel rods

Mortar ---> Cement + Sand + Water

Thermal decompostition

CaCo3 (s) --->  CaO(s) + CO2 (s)

               (HEAT)  ( CaO QUICKLIME)

IN a rotary Kilm

Test for CO2-->  bubble through limewater Ca(OH)2 if it turns milky CO2 is present

1) Ca(OH)2 (aq) + Co2 (g)  ---> CaCo3 (s) (turns milky)+ H2O (l)

2) Acis + carbonate ---> salt + C02 + water (word equation for below)

CaCo3 (s) + 2HCl (aq) ---> CaCl2 (aq) + Co2 +  H20 (l)

THERMAL DECOMPOSITION OF METAL CARBONATES

The MORE REACTIVE the metal, the more stable the carbonate therefore the HARDER it is to decompose.

Ma2CO3 does NOT compose

CaCo3 - Does so at high temp 0---> Oxide3 + Co2

CuCo2 - readily decomposes ---> Oxide + Co2

Calcium Hydroxide used by farmers to neutralize acis soil (Ca(OH)2 is alkali)

CaCo3 (s) ----> (heat)  CaO (quicklime) ---> (water) Ca(OH)2 (s)(Slaked lime exothermic reaction) ---> (water fliter) Ca(OH)4 (aq) ---> (+Co2)  Caco3 (s) Then it starts again!

More reactive the element more stable the ore so harder to extract metal.

Elements below carbon in the reactivity seris are extracted by reduction

Aq/Au are found in there native state  and are extracted by mining or panning.

Extraction of iron (blast furnace ... reduction)

Fe2O3 (s) + 3Co (g) ---> 2Fe (l) + 3Co2 (g)   Reducting agent is CARBON MONOXIDE

Makes cast iron  (4% carbon)

Steels

Carbon steels 0.03-1.5% carbo. Cheapest. Knives cars building work ect

Low alloy steels 1-5% trace metals

High alloy High % of trace metal therefor expensive

Stainless steel chromium - nickel steels

Strong low density do not corrode

Aluminium - extracted by electroylis Impure Al2O3 is purified thenmatled (high temp) Lots of electricity therfore very expensive.

Properties - light, good conductor, can be hammered, dosen't corrode as protected by a oxide layer.

Titanium - Ore is reacted with more reactive metal (Na) ( Nb: Ore - Tioxide- converted to tichoride then react TiCl4 with sodium)

Properties -Srong resistant to corrosion (protective oxide layer)  Used for aircrafts, jet engines, neclear reactors, hip joints.

Copper is extracted from coper rich ore

method 1) add sulfuric acis to make copper sulfate - then extract copper

Method 2) SMELTING strangly hat ore in a blast furnace. Below

Malachite (CuCO3) is heated (CuCo3 (s)--- Cuo (s) + Co2 (g)) Then add H2SO4 to CuO (CuO + H2So4 ---> CuSo4 + H2O) then add iron to DISPLACE the copper (CUSo4 + Fe ---> FeSo4 + Cu)