C4.1 Flashcards
Where are the Group 1 elements and what are they also called?
In a vertical column in the far left of the periodic table and they are also called the alkali metals
What are some properties of Group 1
They are shiny when freshly cut, goof conductors of electricity and solid as room temp. They are very soft.
What is the hardest Group 1 metal
Lithium and it’s softer as you go down the group
What are the trends as you go down in Group 1
The density increases (sodium is unexpected) and their melting point decreases
Why are Group 1 metals stored in oil
This is as they react rapidly with the oxygen in the air and with water
What happens when Group 1 reacts with water?
They react with water to produce hydroxide of the metal and hydrogen
E.g if sodium reacts with water = sodium hydroxide and hydrogen
What happens when an Group 1 reacts with dilute acids?
- salt and hydrogen gas is produced
- these reactions are more violent than with water so dangerous to do in lab
What is the trend in reactivity as you go down in Group 1
The reactivity increases
How does Lithium react?
It fizzes steadily and slowly disappears
Who’s does Sodium react
It melts to form a silvery ball, fizzes vigorously and quickly disappears
How does potassium react
It floats on the surface and immediately ignites the hydrogen gas produced and burns with a lilac flame and then it disappears quickly
How does rubidium and caesium react with water?
- very violently with water - tend to explode when they get wet
How do you explain the trend in reactivity in Group 1
All their atoms have one electron in the outer shell. They lose their electrons in the outer shell in reactions and form ions with a positive charge.
M —> M+ + e-
The easier it is for the atom to lose the electron the more reactive it is. Elements lower down the group have elements with more shells and therefore have weaker electrostatic forces between the positive nucleus and negative electron
Where are the Group 7 elements found
Vertical column in the right of the periodic table
What is Group 7 also called
The halogens
What are the properties of Group 7
They are non metals and diatomic molecules
Weak imf
Brittle in the solid state
Poor conductors of electricity
What is fluorine in room temperature
Fluorine is a pale yellow gas
What is chlorine in room temperature
It’s a green gas
What is bromine in room temperature
It’s an orange brown liquid that vaporises easily
What is iodine are room temperature
It’s a shiny grey-black crystalline solid that sublimes to form a purple vapour
What are the trends in Group 7
The density increases and you go down
The melting and boiling points increase
What does Group 7 react with
They react with metals to produce salts
They react vigorously with Group 1 metals esp if it’s heated first
What happens to the reactivity in Group 7 as you go down the group
The reactivity decreases (opposite to alkali metals)
How do you explain the trends in activity in Group 7
They have similar chemical properties because all their atoms have seven electrons in the outer shell. They gain an electron in reactions to complete the outer shell and form one with a single negative charge.
X2 + 2e- —> 2X-
It’s easier for the halogen to gain an electron, the more reactive it is. As you go down the group, there are more electron shells acting as shields which means there is a weak electrostatic attraction between the positive nucleus and negative electron, making it harder to gain an electron.
What can halogens react with
Halogens can react with halides in a solution
What is a Halide
Compound which contains a Group 7 element and another element which is usually a hydrogen or metal
Hydrogen chloride and sodium chloride are halides
What is a Halide ion
It’s a negative ion formed by Group 7 elements ( e.g. chloride ions from chlorine)
When will a halogen replace a halogen
It’s will replace a less reactive halogen from its Halide ions in a solution
What does chlorine displaces
Chlorine displaces bromine from bromides and iodine from iodises
What does Bromine displace
Bromine displaces iodine from idolise but it can’t replace chlorine from chlorides
What can iodine displace
Iodine can’t displace chlorine from chlorides or bromine from bromides
What pattern do all halogen reactions follow
(Halogen 1)2 + 2(halogen 2) - > (halogen 2)2 + 2 halogen 1
E.g. cl2 + 2KBr —> Br2 + 2KCl
How can you use halogen displacement reactions to confirm the order of reactivity for chlorine, bromine and iodine?
- Wear eye protection and place a small volume of potassium chloride solution in a spotting tile
- Add a few drops of bromine water
- Note observations in a table
- Repeat for the other pairs of solutions
Asthmatics = extra care to not breathe in any chemical fumes
What type of a reaction is a halogen displacement reaction
Redox reaction
What happens to the halogen that displaces the other one
It gains electrons so it’s reduced
Cl2 + 2e- —> 2Cl-
What happens to the halogen displaced
It loses electrons so it’s oxidised
2Br- —> Br2 + 2e-
What kind of solutions and compounds do hydrogen halides form
Acidic solutions
Covalent compounds
Where is Group 0 found and what are they also called and why?
They are found on the right and called noble gases because they only take part in very few reactions
What are group 0 and what state are they at RTM
They are non metals and colourless gases at room temperature
What is group 0 so unreactive?
They have a complete outer shell of electrons so they don’t have a tendency to gain or lose electrons to form ions fair to share electrons to form molecules in solutions.
How many electrons does Group 0 have in their outer shell
They have 8 except for helium which has 2
Are noble gases diatomic or monatomic?
They are monatomic with weak forces of attraction between them which are easily overcome by heating
What is the trend is boiling points in Group 0
They all have very low boiling points the boiling point increases as you go down the group as the attractive forces between the atoms get stronger
What is the trend in density in Group 0
They all have very low densities as their atoms are far apart in the gas state so there is very little mass in a given volume. As you go down the group, the density increases
What noble gases have been in involved in no reactions?
Neon and helium
Where are transition metals found
Places between group 2 and 3
What are the properties of transition metals
They are all metals and their properties are typical metals.
- shiny when freshly cut
- good conductors of electricity
- strong
- malleable (hammered into shape)
How are the transition metals compared to alkali metals
- they are stronger and harder
- they have higher densities
- they have higher melting points (except for mercury which is the liquid state at room temperature)
- relatively unreactive
So useful for making everyday objects
What are the chemical properties of transition metals
They are less reactive than the alkali metals and they react very slowly, if at all
How does rusting happen
Iron reacts slowly with water and oxygen to produce rust which is hydrates iron (III) oxide
Which elements don’t react with water or oxygen at all
Gold, platinum and iridium
What kind of compounds do transition metals produce compared to alkali metals
- alkali metals = white or colourless ionic compounds
- transition metals = coloured ionic compounds
What kind of ions do transition metals form
- They can form more than one type of ion (e.g. Iron (II) oxide, FeO has Fe2+ ions and iron (III) oxide, Fe2O3, has Fe3+ ions
- Roman numerals in brackets tell you the charge on the metal ions
What are transition metals good at?
Good catalysts
What metals are used in catalytic converters
Platinum, rhodium and palladium
What do catalytic converters do
They convert harmful gases in vehicle exhaust fumes into less harmful ones before being released into the environment
What are catalysts
Substances that increase the rate of chemical reaction without being used up.
What type of ions do metals form
They form positive ions as they lose electrons
What makes metals in general more reactive
The more easily metals lose electrons, the more reactive the metal is.
When can a metal react with water or dilute acids
It’s can react with water or dilute acids if it’s more reactive that hydrogen
What do metals produce when they react with water
- They produce a metal hydroxide and hydrogen (h2)
- or if it’s a less reactive metal then it reacts with metal to produce a metal oxide and hydrogen
What do metals produce when they react with acids
They produce a salt and hydrogen (h2)
What reactions can be used to put metals in order of reactivity and how do we know how reactive it is?
Reacting then with dilute HCl or with water
- the more reactive the metal then the greater rate of hydrogen production = more vigorous bubbling (eye protection worn)
How can you react metals with water or HCl to find our the reactivity?
- Place 2cm cubed of water in a test tube
- add a small piece of metal and note the rate of bubbling
- if very little or no bubbling then gently warm the water to see if the bubbling starts or increases in rate
- repeat with other metals and with HCl instead of water
Why should you not boil the water or the HCl when reacting with metals?
When it boils then bubbles will be produced, so you would not be able to tell if the bubble were due to a reaction or not. It would also be unsafe to boil HCl.
What are metal displacement reactions?
A more reactive metal can displace a less reactive metal from solutions of its compounds.
What happens when copper reacts with silver nitrate solution?
What colour does the solution turn and what type of crystals form?
Copper is more reactive than silver so it displaces silver from silver nitrate solution. Copper nitrate is formed, which is blue.
Cu (s) —> Cu2+ + 2e- oxidation
Ag+ + e- —> Ag (s). reduction
What type of a reaction is a metal displacement reaction and what happens to each compound?
It’s a redox reaction. The metal that is more reactive and displaces is getting oxidised and loses electrons. The metal that is displaced is reduced and gains electrons.
What’s the reactivity series in order from most to least reactive?
- potassium
- sodium
- calcium
- magnesium
- aluminium
- (carbon)
- zinc
- iron
- tin
- lead
- (hydrogen)
- copper
- silver
- gold
- platinum
Please stop calling me a cute zebra, it’s totally like hating cute, smart, guys, please.
How will Group 0 react
They don’t react
How will group 1 and 2 react
They are more reactive than transition and other metals
They become more reactive as you go down the group
How will Group 7 react
They are non metals that become less reactive as you go down the group
What might happen when reactive non metals react?
They might form covalent compounds with each other
What might happen when reactive non metals react with metals?
They may form ionic compounds
Describe how to carry out a displacement reaction and how it can be useful
They can confirm the order of reactivity for metals such as magnesium,zinc and copper.
- place a small volume of copper (III) sulphate solution in a spotting tile well
- add a piece of magnesium
- note your observations on a table
- you will need to repeat for the other pairs of solutions
Wear eyes protection throughout the practical.
What is steel/Iron an alloy of
Alloy of carbon and iron
What is silicon-manganese an alloy of?
Manganese, silicon, carbon and iron
Where is silicon-manganese used?
It’s used in structural components and springs
What is the most used alloy of manganese?
Ferromanganese
What is ferromanganese used for?
- tools
- heavy duty machinery
- railroad tracks
- bank vaults
- car parts
- construction components
What are the properties of Nickel?
- resistant to corrosion
- superalloys are resistant to high temperatures
When is Nickel used as a catalyst?
It’s a catalyst used to hydrogenate oil to produce magnesium
What is 70% of nickel used for
Making stainless steel
What are the uses of stainless steels and nickel in general?
Stainless steel - used in large chemical reactions in stainless steel containers as they are corrosion resistant - pulp and paper - petrol and pharmaceutical (drugs) Nickel - batteries - electroplating
What are nickel’s superalloys used in
- jet engines
- gas turbines
What does the addition of chromium into alloys do
- makes it harder
- more resistant to corrosion
- shiny on the surface
What are the applications of stainless steel when make with chromium?
- car bodies
- plating for ships
- construction
- chemicals and petroleum equipment
- cables
- eating and cooking utensils
What is electroplating and what are the benefits of it?
Thing layer of metal is attached to the surface of another metal and this protects it from corrosion and gives it a shiny surface.
What is the use of chromium in refractory bricks?
Refractory bricks can withstand very high temperatures by reflecting heat and is used to line high temperature ovens.
When is chromium used as a catalyst?
It’s used a catalyst in the production of polythene.
What alloy of copper are good in construction?
Brass and bronze are ver strong allots and are therefore used in construction
What properties of copper makes it good for electrical wiring?
- highly conductive
- relatively inexpensive
What are the other uses of copper alloys?
- roofs
- heating and plumbing systems
- structure of buildings
Give examples of 2 copper alloys that have been developed from special purposes
- gun metal are used for guns (90% copper and 10% tin)
- money metal is used for 1p and 2ps as it’s resistant to corrosion (alloy of copper and nickel)
When is iron used as a catalyst
It’s a catalyst used in making Ammonia which is used to make fertilisers for farming
Give examples of classifications of the products of iron/ steel
- car
- construction
- containers, packaging and shipping
- machinery and industrial equipment
- rail transportation
- oil and gas industries
- electrical equipment
- appliances and utensils
- catalysts
What is the most important use of cobalt and when are they used
In superalloys which are used in situations where metals are places under extreme stress and often at high temperatures
Why is a cobalt superalloy used in a gas turbine
A gas turbine has many blades, where hot, high speed gas pushes against the turbine blades, making them spin very fast. Their movement generates electricity. Cobalt superalloys can cope with the high temperature stress produced in the machine.
Why can cobalt be used in generators and motors?
It’s magnetic so it produces a large magnetic field in electric motors and generators.
What are cemented carbides and how are they used?
It’s when one metal is covered with a fine coating of a second metal, it’s used to make very hard and strong alloys such as those used in drilling tools
What type of alloy can manganese make and what properties does it have?
It makes an alloy with steel and it makes it a hard alloy which is resistant to corrosion and mechanical shock
What alloys are used for aeroplane parts, ship propellers and instruments?
Aeroplane parts = aluminium alloys
Ship propellers = bronze alloys
Instruments = brass alloys
When do metal hydroxides form and metal oxides form?
Hydroxide if metal and water
Oxide is less reactive metal and steam
