Electrolysis and metals Flashcards
What are ores?
Rocky compounds containing metallic elements.
What is a pure ore?
1 singular metal, not fused with any other element.
What is the reactivity series?
Potassium Sodium Calcium Magnesium Aluminium Carbon Zebra Iron Lead Hydrogen Copper Silver Gold
What is the acronym the remembering the reactivity series?
Please Stop Calling Me A Cute Zebra Its Like Hating Cool Smart Guys
What is a displacement reaction?
A metal can displace a metal lower than it in the reactivity series from a solution of one of its salts. Eg Magnesium + Copper Sulphate = Copper + Magnesium sulphate because magnesium is higher than copper on the reactivity scale.
When do you use displacement and when do you use electrolysis?
Displacement is below carbon, electrolysis is above carbon.
What does the reduction of an ore cause?
Reduction involves the removal of oxygen atoms from a chemical or the gain of electrons.
What does the oxidation of an ore cause?
Oxidation involves the addition of oxygen atoms to a chemical or the loss of electrons.
What does OilRig stand for?
Oxidisation is loss of electrons, Reduction is gain of electrons.
How does a blast furnace producing iron work?
- Raw materials on top
- Blasts of hot air come in from bottom
- Oxygen in the blasts of air react with coke to form carbon monoxide.
- This reaction is very exothermic and causes the the temp to get up to 1750*c.
- Carbon monoxide mixes with ironIII to form iron.
FE2O3+3CO - 2Fe +3CO2 - Molten iron runs to the bottom of the furnace.
The molten iron is then used to form various products.
How is aluminium extracted?
Aluminium requires electrolysis to be extracted.
Aluminium oxide is heated to a high temp to make it melt.
THe positively charged al ions move towards the negatively charged cathode. The oxide will move towards the positively charged anode and will be oxidised, losing its electrons. These electrons travel up around the wire and will be transferred to the aluminium (reduction and gain of electrons). The ions then becomes atoms and will fall to the bottom of the tank. The used oxygen then covalently bond as pairs and float away.
What properties do transition metals have?
Malleable High melting points Good conductors of electricity and heat Form ions with different charges Less chemically reactive Forms coloured chemical compounds
How do you identify copper II, iron II and iron III ions?
Add diluted sodium hydroxide solution
What colour does Cu II go?
Blue and jelly like
What colour does Fe II go?
Green and jelly like
What colour does Fe III go?
Rust brown and jelly like
What is electroplating?
Electrolysis process, the purification of copper and the manufacture of sodium hydroxide.
Explain the electrolysis of molten zinc chloride - ZnCl2
1 - chloride ions change into chlorine gas as they give up electrons to the anode.
2Cl- —— Cl2 +2e-
2 - zinc ions are changed into zinc atoms as they gain electrons from the cathode.
Zn+2 +2e- —– Zn
Explain the electrolysis of aqueous salts.
When the salts dissolve in water, positive and negative ions are released. These ions move through the water, attracted to either electrode. During metals like sodium, there are positive ions of the reactive metal and hydrogen ions from the water as well as negative anions. There is competition at the cathode between sodium and hydrogen ions. The hydrogen gains electrons more easily (less reactive, less effort?) than the sodium so hydrogen gas is produced at the cathode. The reactive metal iron stays in the solution and chlorine gas is produced at the anode.
Properties and uses of iron?
Properties - can be magnetised, good conductor of heat. Tough and ductile, stainless steel is resistant to corrosion.
Uses - Magnets, transformer cores, car body panels, cutting tools, railway lines, cutlery.
Properties and uses of aluminium?
Properties - Strong, low density, resistant to corrosion.
Uses - High voltage power lines, saucepans, drink cans, transport parts.
Properties and uses of copper?
Properties - very good conductor of heat, malleable, lustrous, attractive colour.
Uses - in alloys like brass and bronze, water pipes, electrical wires, jewellery and saucepans.
Properties and uses of titanium?
Properties - hard, strong, low density, high melting point, resistant to corrosion.
Uses - Jet engine and spacecraft parts, industrial machine parts, medical implants, jewellery and sports equipment.
What are alloys?
Alloys are mixtures of 2 or more different metals made by combining the molten metals.
What is brass made out of?
Copper and zinc.
What is bronze made out of?
Copper and tin.
What is stainless steel made out of?
Iron, carbon and chromium.
Step by step list to be applied to the answering of half equations in electrolysis?
1 - identify elements and write down ions from ion sheet.
2 - Positively charged ions gains the amount of electrons as its charged.
3 - Negatively charged electrons loses the amount of electrons as its charged.
4 - Gasses go round in pairs so balance the equation (covalent bonding)
What is the test for hydrogen?
Put a lighted splint into the gas. If it is hydrogen, there will be a squeaky pop.
What is the test for oxygen?
Put a glowing splint into the gas. If it it oxygen the splint will relight.
What is the test for carbon dioxide?
Lime water turns cloudy of CO2 has ran through it. (Blowing through the straw).
