The Periodic table Flashcards
What is a “group” in the periodic table?
A column of the periodic table
What is a “period” of the periodic table?
A row of the periodic table
Where are metals found in the periodic table?
To the left of the zig zag line
Where are non-metals found in the periodic table?
To the right of the zig zag line
What pattern happens in groups of elements?
They have similar properties which gradually change down the group
How do you know how many valency electrons an atom has?
The group number indicates the amount of valency electrons
Where are alkali metals found in the periodic table?
In group 1 of the periodic table?
What are alkali metals’ physical properties and trend in reactivity?
Properties - relatively soft metals, low melting points compared to most metals, low density
Trend in reactivity - increases down the group
How do alkali metals react with water?
Vigorously
Where are halogens found in the periodic table?
Group 7
What is a halogens molecular structure?
Diatomic non-metals
What are halogens melting points?
Low melting points that increase down the group
What are halogens trend in reactivity?
Decreases down the group
What are halogens colour and physical state?
Halogens get darker in colour as you go down the group: Fluorine - yellow gas, Chlorine - green gas, Bromine - Red liquid, Iodine - dark grey solid
What are halides?
Halides are compounds which contain halide ions (F-, Cl-, Br-, I-)
What is a halide displacement reaction?
Where a more reactive halogen will displace a less reactive halogen from a solution of its halide.
Where are transition metals found on the periodic table?
The block in the middle of the periodic table
What are transition metals properties?
High density, High melting points, Good conductors, Pure metals look metallic, Compounds are coloured, Variable oxidation numbers.
What are important uses for transition metals and their compounds?
Good cataylsts
Where are noble gases found in the periodic table?
Group 0
Describe a noble gases’ structure and reactivity
Noble gases have a monatomic non-metal gases structure.
They are very unreactive due to their full outer shell of electrons.
Uses for each noble gas
Helium - Filling balloons and air ships
Neon - Advertising signs
Argon - Providing an inert atmosphere, welding
Krypton - In lasers for eye surgery, in car headlamps
Xenon - In lights
Define what an acid is
A proton (H+) donor
Define what a base is
A proton (H+) acceptor
Define what an alkali is
A soluble base
Which ions are responsible for making a solution acidic or alkaline?
Acidic - H+ ions
Alkaline - OH- ions
What is the difference between strong and weak acids
Strong acids dissociate completely into ions when dissolved in water, weak acids partially dissociate
What is the difference between strong and weak bases
Strong bases dissociate completely into ions when dissolved in water, weak bases do not dissociate completely.
What are the hazards of working with acids and alkalis?
Strong acids and bases are corrosive
Acid + Base =
Salt + water
Acid + metal =
Salt + hydrogen
Acid + carbonate =
Salt + water + carbon dioxide
Base + ammonium salt =
Salt + water + ammonia
Equation for insoluble salt production
Soluble salt + soluble salt –> insoluble salt + soluble salt
What salts are soluble?
All sodium, potassium & ammonium salts
All nitrates
Chlorides except silver & lead chloride
Sulphates except calcium, barium & lead sulphates
What is the Ph scale
The scale which measures the acidity or alkalinity on a scale of 1 to 14
What are three indicators used for the Ph scale
Universal indicator - acid = red/orange/yellow alkali = blue-purple, neutral = green
Litmus = Acid = red, alkali = blue, neutral = purple
Methyl orange = acid - red, alkali - orange, neutral - yellow
What is neutralisation?
Neutralisation occurs when an acid and a base react together
What is an agricultural use for neutralisation?
Acidic soil being neutralised by a base
What is an acidic oxide?
Something that reacts with bases and dissolves in water to produce an acid.
What is a basic oxide?
Something that reacts with acids
What is an amphoteric oxide?
Reacts with both acids and bases
What is a neutral oxide?
Do not react with acids or bases
What does the reactivity series show
It shows the tendency of a metal to form its positive ion when reacting with aqueous ions or oxides of the other metals
What is a displacement reaction?
When a more reactive metal will displace a less reactive metal from its oxide.
What is a thermal decomposition of carbonates reaction?
When a metal carbonate is broken down in a metal oxide and water
What is a thermal decomposition of hydroxides?
Where a metal oxide is broken down into metal oxide and water
What is a thermal decomposition of nitrates?
Where metal nitrate goes to form metal oxide + nitrogen dioxide + oxygen
Why is aluminium not as reactive as expected?
Aluminium is not as reactive as expected because it is coated in a thin film of unreactive aluminium oxide.
What is an “oxidation” reaction
Where oxygen is gained
loss of electrons
increase in oxidation number
What is a “reduction” reaction
Loss of oxygen
gain of electrons
decrease in oxidation number
What is a redox reaction
A reaction in which both oxidation and reduction occur
What is an oxidising agent
A substance which oxidises another substance in a redox reaction
It is reduced
It gains electrons
What is a reducing agent
A substance which reduces another substance in a redox reaction
It is oxidised
It loses electrons
What does “oilrig” stand for
Oxidation is loss, reduction is gain (of electrons)
How does the position of a metal in the reactivity series determine the method used to extract it from its ore?
Unreactive metals - found native or uncombined so extraction is easy
Metals less reactive than carbon - reduction in blast furnace
Metals more reactive than carbon - electrolysis
Refining using electrolysis - some metals which are extracted by reduction may be purified using electrolysis
Name the apparatus and raw materials of iron ore extraction. What are the four steps
Apparatus - blast furnace
Raw materials - Iron ore (haematite), carbon (coke), Limestone.
- ) Coke is burned, giving off heat and carbon dioxide
- ) Carbon dioxide reacts with more coke to make carbon monoxide
- ) Iron oxide is reduced by carbon monoxide to iron
- ) Limestone decomposes thermally to form calcium oxide
What is steel
It is an alloy of iron with other elements
Describe the uses of iron
Mild steel - constructing buildings, making vehicles
Stainless steel - making cutlery, making equipment for use in chemical factories
Definition of electrolysis
The breakdown of a molten or aqueous ionic compound by electricity
Definition of cathode
The electrode connected to the negative terminal of the battery
Definition of Anode
The electrode connected to the positive terminal of the battery
Definition of electrolyte
A liquid that contains ions and therefore conducts electricity
Which electrodes to cations and anions move to
Cations move to the cathode, gain electrons
Anions move to the anode, lose electrons
What is produced at the anode and cathode
Anode - non metal
2Cl- –> Cl2 + 2E-
Cathode - metals
Fe2+ + 2E- –> Fe
What form is zinc found in naturally?
Zinc sulphide a.k.a Zinc blende
List the steps to extract zinc from its compound
step 1.) Zinc sulphide is roasted in air to produce zinc oxide and sulphur dioxide
2ZnS + 3O2 –> 2ZnO + 2SO2
step 2.) Zinc oxide is reduced with carbon monoxide
Zn2+ + 2E- –> Zn
What are the uses of zinc
Galvanising iron
Making alloys
How is copper refined
Copper is refined by electrolysis
Cathode - made of pure copper
Anode - made of impure copper
electrolyte - dilute solution of copper sulphate
result - copper (99.9% pure) will be deposited at the cathode
Uses of copper
Electrical wiring
Cooking utensils
Water pipes
What form is aluminium found in naturally?
Bauxite (aluminium oxide)
What are uses of aluminium
Manufacturing air craft
Overhead electricity cables
Making food containers
What is Brine?
A concentrated solution of sodium chloride
State the products of brine electrolysis?
Hydrogen gas is formed at cathode
Chlorine gas is formed at the anode
Sodium hydroxide is also left in the solution
What are uses for the products?
Hydrogen - Margarine, ammonia, refrigerants
Chlorine - hydrochloric acid, Bleach, PVC, solvents, paints, medicines, weed killers, pesticides
Sodium hydroxide - Soaps, detergents, oven cleaner, biodiesel, paper, textiles, dyes
What is “electroplating”
Using electricity to coat one metal with another
How is electroplating done?
1.) To coat metal A with metal B pass electricity through the following cell
Cathode - Metal A
Anode - metal B
Electrolyte - a solution of a soluble compound of metal B
Uses of electroplating
To make cheaper metal look better
To prevent corrosion
What are three natural sources of sulphur
The pure element - underground and near volcanoes
As a compound in metal ores - e.g. galena
In fossil fuels - coal, crude oil, natural gas
What is produced in the “contact process”
Sulphuric acid
Raw materials used are sulphur or sulfur dioxide, air and water
step 1.) Sulfur is burned in air to make sulfur dioxide
step 2.) SO2 is mixed with more air and passed over a vanadium oxide catalyst at 450C, 1-5 atmospheres pressure to make sulfur trioxide
step 3.) So3 is dissolved in concentrated sulfuric acid to oleum
step 4.) Oleum is mixed with water to produce concentrated sulfuric acid
What are the properties of conc. and dilute sulfuric acid?
Dilute sulphuric acid shows the usual reactions of acids
Conc. sulfuric acid is a dehydrating/ drying agent - it removes water
What are the uses of sulfuric acid?
Fertilisers Paints Fibres Soaps Car batteries
What are the uses of sulfur dioxide?
As a bleach in the manufacturing of wood pulp for paper
As a food preservative (kills bacteria)
What is the composition of clean air?
21% oxygrn
78% nitrogen
0.04% CO2
Rest is mainly argon
Name and explain the process used to separate air into its components
Fractional distillation of liquid air -
Cleaning: Air is cleaned to remove water vapour, carbon dioxide and pollutants
Liquefying: The air is cooled to -200*c
Fractional distillation: The liquid air is warmed to in a fractionating column
What are some examples of greenhouse gases
Carbon dioxide and Methane
How carbon dioxide and methane produced
Carbon dioxide is produced by complete combustion of carbon containing fuels
methane is produced by decomposition of vegetation and is a waste gas from digestion in animals
What problems do green house gases cause
An increase in greenhouse gas levels could cause global warming which might lead to climate change
Name four air pollutants
Carbon monoxide, Sulfur dioxide, Nitrogen oxides, Lead compounds
Explain where these air pollutants come from and the problems they cause
Carbon monoxide - Incomplete combustion of carbon fuels, it is a toxic gas that can bind to haemoglobin which means no oxygen
Sulfur dioxide - Combustion of fossil fuels, cause raspatory issues, dissolves in rain to form acid rain
Nitrogen oxides - causes raspatory (breathing issues) and it can cause acid rain
Lead compounds - car engines using leaded petrol, damages children’s brains, damages the nervous systems of adults
What problems does acid rain cause?
Dissolves limestone/ marble buildings
Lowers Ph in lakes& rivers, kills fish
Kills trees and insects
How do catalytic converters remove pollutants remove pollutants from car exhaust fumes?
Converts carbon monoxide into carbon dioxide
Converts nitrogen oxides into nitrogen
Unburnt hydrocarbons into carbon dioxide and water
What three ways is carbon transferred in the carbon cycle
Combustion
Respiration
Photosythesis
How is water treated in order to make it safe to drink? list the process
- ) Screening - Water is passed through a screen, which traps large particles, e.g. twigs
- ) Coagulation - A coagulant is added to the water to make very fine particles stick together. These are skimmed off.
- ) Filtration - Water is passed through a filter of fine sand to remove any remaining small particles.
- ) Chlorination - Chlorine is added to kill bacteria and other microbes
Uses for water in the home
Drinking, cooking, washing, flushing toilets
Uses for water in farms
As a drink for animals, for watering crops
Uses for water in industry
As a solvent, to wash things, for cooling, manufacture of ethanol
Uses for water in power stations
heated to make steam, which turns the turbines that generate electricity
Three ways to prevent rusting
Coating - coat the metal in paint or grease to prevent oxygen and water from reaching the metal surface
Sacrificial protection - A more reactive metal is attached to iron/steel so that the more reactive metal corrodes instead of the iron/steel
Galvanising - Iron/steel is coated in zinc to prevent air and water from reaching the iron/steel
What is the chemical name and formula of limestone
Calcium carbonate, CaCO3
What is the equation for the thermal decomposition of limestone and the slaking of line?
Calcium carbonate —> Calcium oxide + Carbon dioxide
Slaking of lime - CaO + H2O —-> Ca(OH)2
Uses for limestone
Making iron
Making cement
Uses for lime/slaked lime
Neutralising acidic soil
Neutralising acidic industrial waste products
What is the Haber process
An industrial process for the production of ammonia from nitrogen and hydrogen
N2 + 3H2 —> 2NH3
Where are the raw materials obtained from in the Haber process
Nitrogen - extracted from the air
Hydrogen - from reacting methane with steam or from cracking alkanes
What tempurature, catalyst, pressure is required for the Haber process
Tempurature - 450*C
Catalyst - Iron
Pressure - 200 atmospheres
How can the equilibrium be forced to make more ammonia?
The ammonia is cooled, so that it condenses into a liquid and can be removed
Uses of ammonia
Fertilisers
Explosives
Cleaning products
Why are fertilisers necessary? give four examples of fertiliser, including formulae
Fertilisers make crops grow bigger and faster
examples of fertiliser are Ammonium nitrate NH ₄NO ₃
Ammonium sulphate (NH₄)₂SO₄
Ammonium phosphate (NH4)3PO4
Potassium sulphate K₂SO₄
