Unit 3 Flashcards
What is a metal composed of
Positive ions and delocalised electrons
Are metals conductors of heat
Yes
Are metals conductors of electricity
Yes
What melting and boiling points do they have and why
High as they are held together by strong forces of attraction between ions and atoms
What is the structure of a metal
A metallic lattice structure that is made up of positive ions and delocalised electrons
What happens when a metal reacts with oxygen
A metal hydroxide is produced
What happens when a metal reacts with water
A metal hydroxide and salt is formed
What happens when a metal reacts with an acid
A metal salt is formed as well as hydrogen
What is the electrochemical series
A list of metals based on their reactivity
What is a reduction reaction
When an atom loses outer electrons to become an ion
What is an oxidation reaction
When an ion gains electrons to become an atom
What are the two types of natural metals
Combined
Uncombined
What is an uncombined metal
One which exists naturally, as a singular element (such as gold). Less reactive metals are always uncombined
What is a combined metal
A metal which naturally exists as part of a compound, along with other metals. These tend to be more reactive elements.
What Is an ore
A naturally occurring combined metal compound, from which singular metals can be extracted.
What is the percentage composition of an ore
The percentage of each metal within the ore
What is the equation for percentage composition
% mass=(mass of element/gfm of ore) x100
How can metals be extracted from their ores
- electrolysis
- heating with carbon
- heating
How do you extract very reactive metals and what is produced
Electrolysis
Producing oxygen
How do you extract relatively reactive metals and what is produced
Heating with carbon
Carbon dioxide is produced
How do you extract the least reactive metals and what is produced
Heating
Producing carbon dioxide
What can you call a reaction including both oxidation and reduction
REDOX (or displacement)
When two metals are connected in series in a cell, what is the direction of electron flow
Most reactive metal to least reactive
What is a metals reactivity
A measure of how readily metals lose its outer electrons
What is a plastic
A synthetic material which can change its shape when a force is applied to its and stays like this even when the force is removed.
What qualities do plastics have
+ lightweight
+ waterproof
+ tough
+ electrical insulators
What is a polymer
A family of plastics which are composed of smaller molecules known as monomers.
What is the process in which monomers are reacted together to form a polymer.
Polymerisation
What is a resin
A group of polymer chains
What is the main type of polymerisation
Addition
What happens during addition polymerisation
An unsaturated (alkene) monomer is added with other alkenes, opening their double bond and creating a saturated alkane, which is the new polymer.
How do you name a polymer which has undergone addition polymerisation
You put POLY(name of monomer which it was originally made of)
E.g. poly(ethene)
How do you find the monomer of which a polymer is made
Find the group of molecules that is being repeated
H Ch H Ch H Ch
I I I I I I
-C - C - C - C - The repeating unit is -C - C -
I I I I I I
H H H H H H
Then join the backbone molecules (carbon in this case) to form the unsaturated monomer H Ch I I C = C I I H H
What do you call a polymer that is mad of more than one monomer
A co-polymer
What are the two types of plastics
+ thermosetting
+ thermosoftening
What is a thermosetting plastic
One which does not melt upon heating and cannot be changed from its original shape
What is a thermosoftening plastic
One which melts upon heating and can then be re-shaped
What are the properties of monomers
+ gas or liquid
+ cheap
+ reactive
What are the properties of polymers
+ solid
+ expensive
+ unreactive
What is the order of chemical reactions required to obtain polymers
Crude oil —fractional distillation—> alkanes—‘cat cracking’—> alkenes—addition polymerisation—> polymers
What is radiation
When an unstable atom expels protons neutrons or electrons to gain a stable arrangement.
How is atom stability measured
Proton:neutron ratio
What are the three main types of radiation
- alpha
- beta
- gamma
What is alpha radiation and what are it’s mass and charge
Alpha radian is the emission of a helium nucleus, containing two protons and 2 neutrons.
Charge= 2+ Mass= 4
What is beta radiation and what are it’s charge and mass
Beta radiation are fast moving electrons
Charge = 1- Mass = 0
What is gamma radiation
High frequency electromagnetic waves
Charge and mass = negligeable
What is alpha radiation absorbed by
A sheet of paper
What is beta radiation absorbed by
0.5 cm of lead
What is gamma radiation absorbed by
Thick concrete
What is the rule for nuclear equations
The combined mass and atomic number on both sides of the equation must be equal
What is the half life of a radioactive substance
The time taken for its activity to halve
Is half life affected by any chemical or physical conditions
NO
How do you determine the half life of a substance by using a graph
+ Find a point on the y axis
+ read the value on the x axis
- half the y value DIFFERENCE IN X VALUES = HALF LIFE
- read the x value
What are some uses of radioisotopes in medicine and industry
+ killing cancer cells
+ treat gland swelling
+ DATING
What is dating
A process by which organisms can be dated to their age or how long they have been dead. To do this, the beta emission of the organism is measured as all organisms contain the chemical carbon-14.
What are fertilisers
Chemical or natural substances which are added to soil to increase their fertility by providing it with nutrients and essential elements
What are the three elements that a fertiliser requires at least one of to increase plant growth.
+ nitrogen
+ potassium
+ phosphorus
What is the function of nitrogen
It increases protein production in the plant, allowing it to function efficiently.
What is the function of potassium
It has a role in root formation
What is the function of phosphorus
It has a role in photosynthesis respiration and energy transfer
What is the main producer of fertilisers
Ammonia
What are the properties of ammonia
- clear
- pungent
- colourless gas
What is the name of the process by which ammonia is produced
The Haber process
What is the first stage of the haber process
nitrogen reacts with hydrogen in the presence of an iron catalyst, creating ammonia gas
Temperature = 400 degrees Celsius Pressure = 200 atm
What happens in the second stage of the haber process
The ammonia gas is then condensed into a liquid and the excess hydrogen and nitrogen are recycled (this all happens in an industrial cooler)
What is the equation of ammonia solution with an acid
Ammonia solution + acid —> ammonia salt + water
What is ammonia solution then converted into
Nitric acid
What is the process by which ammonia is converted into nitric acid
The Ostwald process
REVISE OSTWALD PROCESS
NOW
What is the equation to find the percentage of an element in a compound
% mass = (mass of element/ gfm of compound) x100
What colour precipitate forms from calcium ions
White
What colour precipitate forms from copper ions
Blue
What colour precipitate forms from iron (III) ions
Rust
What colour precipitate forms from iron (II) ions
Dark green
If an experiment uses an acid and then silver nitrate, what ions are they testing for?
Halide
What is a precipitate
The product of two solutions, forming an insoluble salt
Will solutions from a precipitate if they are soluble
No
Using the hardie identification technique, what colour are precipitates of ions of:
A= chloride B= bromide C= iodide
A= white B= cream C= yellow
What determines the colour of a flame
Which ions are present in the burning sample
Hey dude
Great job
What metals react with water, oxygen and acids
The very reactive ones (top of the series - sodium)
What metals react with only oxygen and acid
From sodium-lead
What metals react with only oxygen
The least reactive metals
What Is electrolysis
The décomposition of a metal compound into its separate elements by passing electricity through it.
What current does electrolysis require and why
DC as a,terra ting current produce explosive form of hydrogen and oxygen
What is an electrolyte
An electrically conduction solution containing ions
What is the name of the connecter that completes the circuit in a cell
Ion bridge
What does the voltage of a cell depend on
How far art the two metal electrodes are in the electrochemical series. The further apart, the higher the voltage.
What happens to the mass of the electrodes during this reaction and why
The mass decreases as the atoms of the metal in the electrode lose electrons and turn into ions, flowing into the solution instead.
What is a reducing agent in a redox reaction
The element that is being oxidised and vice versa
What is the name of the rule to figure out the reactions in a cell
The Z rule
What do you do to the upper line in the Z rule
Invert it
What catalyst is used in the haber process
Iron
What catalyst is used int he Ostwald process
Platinum
