Unit 1 Flashcards
Where are protons and neutrons found in the atom?
Nucleus
Where are electrons found in an atom?
They orbit the nucleus
What does the atomic number tell you?
The number of protons
What does the mass number show?
The number of protons and neutrons
What does the group number show?
The number of electrons in the outer shell
Why are noble gases unreactive?
They have a full outer shell
What is the general formula for the saturated compound?
CnH2n+2
What is the general formula for the unsaturated compound?
CnH2n
What is an isotope?
A number with the same amount of protons, different number of neutrons
What is the formula of alkanes?
CnH2n+2
What is the formula of alkenes?
CnH2n
What is the unsaturated compound?
CnH2n
What is the saturated compound?
CnH2n+2
What is the formula of calcium carbonate?
CaCO3
What is limestone also known as?
Calcium carbonate
Is calcium carbonate a compound or mixture?
It is a compound
What does calcium carbonate break down into through thermal decomposition?
Calcium oxide and carbon dioxide
What is heated in a kiln to make cement?
Clay and limestone
What is used to make mortar?
Cement, sand and water
What happens to limewater when carbon dioxide is present?
It turns cloudy
Calcium oxide reacts with water to create what?
Calcium hydroxide
How do you break down limestone?
Thermal decomposition
What colour is calcium oxide when it is hot?
Yellow
What colour is calcium oxide when cold?
White
How do you produce calcium oxide from calcium carbonate?
Thermal decomposition
What is the formula for calcium oxide with water?
CaO + H2O -> Ca(OH)2
What is a benefit of limestone quarrying?
Local employment
What is produced when Limestone is thermally decomposed?
Calcium oxide and carbon dioxide
Why is it difficult to thermally decompose elements in group 1 in class?
Bunsen burners cannot reach a high enough temperature
What is mixed with limestone and sodium carbonate to create glass?
Sand
Which two ways can calcium carbonate be reacted?
Calcium carbonate and with acids
What type of rock is limestone?
Sedimentary
How does limewater convert into limestone?
Carbon dioxide is bubbled through it
What compound dissolves in water to form limewater?
Calcium hydroxide
Carbonates react with acids to create what?
Carbon dioxide
What can calcium hydroxide be used for?
Neutralising acidic fields
How is concrete made?
Sand and aggregate
What are the negatives of limestone quarrying?
- Make the landscape ugly
- Processes cause loud noises
- Destroys habitats
- Transport causes pollution
What is a negative of cement factories?
They create lots of dust
How is limestone used in a power station chimney?
It neutralises the sulfur dioxide
Which is more reactive, sodium or potassium?
Potassium
What are the trends as you go down group 1?
- More reactive
- Lower melting point
- Lower boiling point
What are the characteristics of transition metals?
They are good conductors of heat and electricity
What is an ore?
A rock that contains enough metal to make it economic to extract the metal
How are more reactive metals extracted?
Electrolysis
How are less reactive metals extracted?
Reduction with carbon
How is copper purified?
Electrolysis
Why is copper useful for wiring?
It’s soft so easily bent and a good conductor of electricity
What makes copper useful for plumbing?
Its a good conductor of heat and doesn’t react with water
What is an alloy?
A mixture of two elements, usually metals
Why are alloys harder than pure metals?
They contain atoms of different sizes, which distort the regular arrangements of atoms, making it more difficult for layers to slide over one another
What do all alkali metals have in common?
They need to be stored in oil and handled with forceps
What determines whether an ore can be extracted by reduction?
Metals lower than carbon in the reactivity series must be extracted by reduction
What happens when an ore is reduced?
Oxygen is removed from it
What is a negative of electrolysis compared to reduction?
It is much more expensive as it uses more energy
What is usually the electrolyte in electrolysis?
A metal salt solution made from the ore e.g copper sulfate
Explain how copper is purified?
- Electrons are pulled off copper atoms at the anode, causing them to go into the solution as Cu2+ ions
- Cu2+ ions near the cathode gain electrons and turn back into copper atoms
- The impurities at the anode drop as sludge, whilst pure copper atoms bond to the cathode
Why is electrolysis used in the extraction of copper?
Smelting only gives an impure copper atom
How is copper extracted from a solution?
Displacement using a more reactive metal
What are the new methods of extracting copper ores?
Bioleaching and phytomining
What is bioleaching?
Bacteria are used to separate copper from copper sulfide. The solution produces from this process contains copper
What is the disadvantage of the new methods of extracting copper?
They are slower and produce less copper
Why is it important to recycle metals?
- They are finite
- Extracting new metals causes pollution
- Saves money due to using less energy
When is aluminium most useful?
As an alloy
What are properties of aluminium and titanium?
Corrosion resistant and low density
Why would aluminium be good for building an aeroplane?
Strong, malleable and light
What is a use of titanium?
As a hip replacement
What are some downfalls of metals?
- Some corrode when exposed to water and air
- If they corrode, they lose strength
- Metal fatigue
Which types of steel are made from iron?
- Low carbon steel (0.1% carbon)
- High carbon steel (1.5% carbon)
- Stainless steel (chromium added)
Why is crude oil called a fossil fuel?
Because it is formed from the remains of ancient sea creatures
Compared to large hydrocarbons, small hydrocarbons are…
More volatile
Is the top of an oil fractioning column warmer or colder than the bottom?
Colder
What happens to a liquid during its separation from a mixture by distillation?
Evaporation followed by condensation
Which fraction has the largest carbon chain?
Bitumen
What is a use of kerosene?
Aeroplane fuel
How do geologists find oil?
They study the rock structures
Which hydrocarbons are less efficient?
Those that have a longer chain
What is cracking?
When long hydrocarbon chains are converted into smaller hydrocarbon chains
What is a use of bitumen?
Tarmac
What is crude oil made up of?
Mostly alkanes
If a hydrocarbon molecule chain is shorter?
- It is less viscous
- It is more volatile
- It is more flammable
What does volatile mean?
More volatile means it turns into a gas at a lower temperature
What are the negative gases produced by fossil fuels?
Sulfur dioxide and carbon dioxide
What happens if partial combustion takes place?
Carbon monoxide and soot is released
How are sulfur dioxide emissions reduced?
The sulfur is removed before the fuel is burnt, or they are removed after combustion in power station by Aid Gas Scrubbers
What causes global dimming?
The soot that is released when fossil fuels are burnt
What is the result of global dimming?
Sunlight is reflected back into space
What are the alternate fuels being developed?
Ethanol, biodiesel and hydrogen gas