AQA Core Chemistry - C1.1 - C1.6 Flashcards
What is a compound?
Two or more elements chemically combined
What is the charge on a proton?
Positive
What does the atomic number tell us?
The number of protons and electrons which the atom has
What does the mass number tell us?
The number of protons and neutrons the atom has
How do you work out the number of neutrons?
Mass number - atomic number
How many electrons can fit into the first 3 shells or orbitals?
1st = 2, 2nd = 8, 3rd = 8
What does the group number on the periodic table tell us?
The number of electrons in the outside shell - each element in the group will have the same number of electrons in their outer shell
What does the period (row) number tell us?
The number of shells the element has
What are elements in Group 0 called and why?
Noble gases as they are unreactive
What is the formula of calcium hydroxide?
Ca(OH)2
cement + sand + mortar = ???
concrete
Limestone + clay = ???
cement
Limestone + sand + sodium carbonate = ???, Under what condition does this have to be under (extra mark)
glass, strong heat
Chemical name for Limestone…
calcium carbonate
Breaking down a chemical by heating is called…
thermal decomposition
Chemical Equation for thermal decomposition of limestone…
calcium carbonate = calcium oxide + carbon dioxide
Lime water is a test for…
carbon dioxide (turns limewater milky)
What is a metal ore…
A metal in its natural state
What is native state…
metals are so unreactive they are found as their elements e.g. Gold
What is the best way to extract a metal from its ore…
using the reactivity series (i.e. displacement/ reduction)
Metal oxide + carbon = two products. What are they?
metal + carbon dioxide
Removal of oxygen is called…
reduction reaction
Metal containing other elements is called…
alloy
What is carbon steel used for?
cars, knives, containers, structural steel
What are the properties of high carbon steel?
very strong, but brittle
Main advantage of stainless steel?
Does not rust
A property of copper is…
Very soft (Also great conductor of heat/electricity)
Name 3 (of a possible 4) properties of transition metals…
good conductors of heat and energy, hard tough and strong, malleable, high melting points
Name two cheaper, more environmental friendly ways to extract copper
bacteria (bioleaching) and plants (phytomining)
Which two elements resist corrosion and are therefore very useful?
aluminium and titanium
What are the disadvantages of the two transition elements that resist corrosion (extra mark - state them)
take a lot of energy to extract from their ores and therefore are expensive - Al and Ti
Disadvantage of electrolysis…
very expensive due to high temperatures and electricity needed. Lots of energy
Why is aluminium recycling important?
takes less energy to produce the same amount from recycled metal than from its ore by extraction
Describe a blast furnace…i.e. what goes in, what comes out, conditions required
iron ore, coke and limescale at the top, slag and iron produced at the bottom, hot air in at bottom, out at top
What gases come out of the blast furnace?
Carbon reacting with oxygen = Carbon dioxide OR carbon monoxide and nitrogen (from the air unchanged)
Properties of low carbon steel?
soft, easily shaped, less likely to shatter than steel
Example of an iron alloy
steel
How are metal atoms arranged (eg.in iron)?
in rows in layers that SLIDE
Explain how iron is extracted
reducing it with carbon in blast furnace
% of carbon in mild carbon steel? Uses of this (extra point)?
less than 0.1%, easily shaped (used in cars)
Carbon steel has what % range of carbon in it?
0.03 - 1.5%
Explain the process which produces 85% of our copper…
smelting - heat copper ore strongly in air, this crude copper is used as anodes in electrolysis cells to create pure 99.9% pure copper
Name and describe the process of aluminium extraction…
electrolysis, electric current passed through Al oxide at high temperatures
Name and describe the process of titanium extraction…
displacement using Na or Mg (use electrolysis first)
Name the process of removing copper from it’s ore, by heat and electrolysis?
smelting
Name a problem with processing copper ore…
uses a huge amount of electricity and therefore costs a lot of money
Name two physical and one chemical advantageous property of copper…
conducts electricity and heat, does not react with water
Why can’t we use carbon to displace aluminium from its ore?
because it is a reactive metal and higher in the reactivity series than carbon
Why is titanium used to make artificial hip joints?
it is strong and resistant to corrosion
What are the two ways of extracting copper from high-grade copper ores?
- Add sulphuric acid and then use electrolysis 2. smelting (roasting) in a furnace
What are the two ways of extracting copper from low-grade copper ores?
phytomining and bioleaching
What are the disadvantages of phytomining?
Plants take a long time to grow and the process is NOT continuous
What are the disadvantages of bioleaching?
Slow process, still need to use electrolysis
What are the advantages of bioleaching?
Can use low grade copper so can use scrap iron
Name 3 benefits of using metals in construction…
Steel is strong for girders in buildings, aluminium alloys are corrosion resistant, copper is a good electrical conductor
Name 3 drawbacks of using metals in construction…
Iron and steel can rust, metal ore exploitation causes pollution, metals are expensive
Name the process of separating crude oil…
fractional distillation
What is distillation?
separates liquids with different boiling points
What is a hydrocarbon?
molecule containing only hydrogen and carbon
Give a general equation for butane…
C4H10
Alkanes contain as much hydrogen as possible. This means it has all single bonds. This makes them…
saturated
2 properties of short hydrocarbon molecules (e.g methane)…
lower boiling point, high volatility, low viscosity, flammable
2 properties of long hydrocarbon molecules…
high boiling point, low volatility, viscous, smoky flame
What happens to the temperature up the fractioning column?
gets cooler
What is the process that happens when gas reach their boiling points?
condensation
What are polymers?
Many monomers (small molecules) that join together to form long chain polymers
When hydrocarbons burn in air they produce…
carbon dioxide, water
What is crude oil?
mixture of many hydrocarbon compounds
Name 4 products from the fractional distillation process…
petrol, naphtha, kerosene, diesel oil, lubricating oil, greases and waxes, fuel oil, bitumen
Impurities in fuels produce…
other substances which may be poisonous and cause pollution
Sulphur dioxide causes…
acid rain
What is incomplete combustion?
where carbon monoxide is formed instead of carbon dioxide due to a lack of oxygen
How does nitrous oxide form in cars?
high temperatures cause N and O in air to react
Why is nitrous oxide dangerous , and state what it can cause (extra mark)
poisonous. Can cause asthma or acid rain
What type of hydrocarbons do diesel engines use?
larger molecule hydrocarbons
Why is ethanol useful in cars?
carbon neutral , easier to grow in economically poor countries, save crude oil supplies
What is in biodiesel?
renewable fuel made from new or used vegetable oil
What is the general formula for an alkane?
CnH2n + 2
What problem does plastic cause if burnt?
toxic gases
What is cracking?
Breaking down of large molecules into smaller ones - it forms a mixture of alkanes and alkenes
Why does crude oil need to be cracked?
Longer chains are less useful (less in demand) as short chains burn better. Supply is of long chains, demand is for short.
A use of smart polymers…
wound stitches, hydrogels
Describe global warming…
warming of the earth due to the greenhouse gases in the atmosphere trapping infra-red radiation from the surface
