C3 Flashcards
Properties of the alkali metal group 1 ?
Low mp
The melting and boiling point decreases as we go down the group
Why does the alkali metal become more reactive as it goes down the group ?
The elements becomes more reactive down the group because it becomes easer for them to lose their outermost electrons this is due to the atom increasing in size found down the group
Why is the alkali metals stored under oil ?
Because they react very vigorously with oxygen and with water
Properties of group7 the halogens?
The mp and bp increases as you go down the group
Less reactive as you go down the group
Poor conductor of heat and electricity
Why is the elements less reactive as you go down group 7 ?
Because it becomes harder for them to gain an electron . This is due to the atoms increasing in size going down the group
In the early 1800s Wattwood are too obvious way to categorise elements ?
Their physical and chemical properties
Their relative atomic mass
What were New Zealand’s law of octaves ?
You noticed that every eighth element had similar properties and so he listed some of the known elements and roles of seven
Why was. Newlands law on octaves criticised?
This was because his groups contained elements that didn’t have similar properties e.g. carbon and Titanium
He mixed up metals and nonmetals e.g. oxygen and iron
He didn’t leave any gaps for elements that hadn’t yet been discovered
What did Mendeleev do differently to Newlands ?
Mendeleyev put the elements in order of atomic mass like a new learns that he had to leave gaps in order to keep elements with similar properties in the same vertical column known as groups
He was prepared to leave some very big gaps in the first two rolls before the transition metals come in on the third rows
The gap that Mendeleev had left was really Clever because…
They predicted the properties of undiscovered elements and when they were phone they fitted the pattern
What are properties of transition elements ?
They are good conductors of heat and electricity
they are very dense strong and shiny
Transition metals are much less reactive than group for metals and they don’t react vigourously with water or Oxygen
They have a higher melting point how much denser and stronger and Harder then group 1 Metals
What are the two types of water?
There is hard water and there is Softwater
What are the two affects of hard water
Hard water makes scum and scale
What causes hard water?
Hard water is caused by calcium and magnesium ions
What are the advantages of hard water?
Calcium irons are good for healthy teeth and bones
Studies have found that people who live in hard water areas on at less risk of developing heart disease and people who live in soft water areas
What are the two types of hard water?
Temporary hardness And Permanently hardness
What is temporary hardness caused by
Is caused by the hydrocarbonate Ions HCO3
What is permanent hardness caused by?
Is caused by the dissolved calcium sulphate
What are the advantages of hard water?
Calcium irons are good for teeth and bones
Study has shown that hard water is good for your heart
Some people prefer the taste of hard water
What are the disadvantages of hard water ?
Hard water poured with Tom which is where calcium and magnesium irons are presented in the water
you need more soap this is because calcium and magnesium reacts with the soap so does not foaming as you would like
Lime scale
What are different ways to treat hard water?
Washing soda- sodium carbonate
This reacts of the calcium ion in the hard water to make insoluble participate of the calcium ions and magnesium ions
the sodium ion Are left in the water
Ion exchange Column
Sodium ions can be exchanged for calcium or magnesium ion in the water that runs
what is a disadvantage of using a ion exchange column?
Columns need replenishing with more sodium ions after a while
What are the method to used in a water treatment plant?
The water passes through mashed screen to remove the bits like twigs
chemicals are added to make solids and micro stick together and fall to the bottom
water is filtered through a gravel bed to remove all the solid
Water is then chlorinated to kill off any harmful microbes left.
What are some advantages to add fluoride into water
It’s good for your teeth and bones and for people who have poor dental hygiene
Only a small amount of fluorine is been added to the water
There is no evidence that there is any harm for a fit of flooring been in the water apart from fluorosis
What are the disadvantages of adding fluoride into water?
Studies have shown exes fluoride can affect the brain
Although with a small amount you can’t set limits as you can’t control people intake of the water
It is ethnically wrong to give people treatment they have not consented to
Water is a natural resource describe the process involved in the water cycle?
Evaporation
Condensation
precipitation
Surface run-off
Define an exothermic reaction?
An exothermic reaction is one which gives out energy to the surrounding usually in the form of heat and usually shown by a rise in temperature
Define what an endothermic reaction is?
And endothermic reaction is one which takes in energy from the surrounding usually in the form of heat and usually is shown by fall in temperature
What type of energy reaction is breaking bonds ?
Endothermic reaction this is because energy must always be supplied to break existing bonds
Endothermic reaction has a positive energy change so more energy is needed to break existing bonds done is released when new bonds are made
What type of energy reaction is bond formation ?
Energy is released when you bonds are formed so born formation is an exothermic process they have a negative energy change so more energy is released when you bonds are made then is needed to break existing bonds
Define what activation energy means?
Activation energy is the minimum amount of energy required for a chemical reaction to occur
How does a catalyst affect the activation energy?
The catalyst to lower the activation energy this means the reaction will happen so easily and more quickly
What does a reversible reaction mean?
Is whining where the products of the reaction can them self react to produce the original reactants
In other words the reaction can go both ways
What will happen if a reversible reaction takes place in a closed system(this is where none of the reactants or products can escape)
A state of equilibrium will be reached an equilibrium means that the amount of reactants and products I will reach a certain balance and stay there
The overall effect is new because the forward and reverse reaction cancel each other out and the reaction taking place at exactly the same rate in both direction
How can you move the position of equilibrium(The relative amount of reactants and products) ?
It depends very strongly on the temperature and pressure surrounding the reaction
How does temperature in a reversible reaction affect the position of the equilibrium?
If you raise the temperature there endothermic reaction will increase to use up the extra heat
If you reduce the temperature there exothermically action will increase to give out more heat
How does pressure in a reversible reaction affect the position of the equilibrium?
If you raise the pressure it will encourage the reaction which produces less volume
If you lower the pressure it will encourage the reaction which will produce more volume
What is the functional group of alcohols
OH
What is the general formula of an alcohol
CnH2n +1OH
The first free alcohol have similar properties list some of them ?
Alcohols of flammable they burn in air to produce carbon dioxide and water
The first three alcohols only dissolve completely in water to form neutral solution
They also react with sodium to give hydrogen and alkoxides
What are the first 3 alcohol in the homologous series?
Methanol
Ethanol
Propanol
Alcohols are used as solvents
Why are they very useful solvents in industry?
This is because they can dissolve substances that water can’t dissolve
Ethinyl is the solvent for perfume then aftershave lotion it to mix well with both the oil which gives the smell and the water that makes up the bulk
Methylated spirits is ethanol with chemicals added to it if you think clean paint brushes and as a fuel
What is the functional group of a carboxylic acid?
COOH
What is the first names of a carboxylic acid?
Mea
What are the first 3 carboxylic acid ?
Methanoic acid
Ethanoic acid
Propanoic acid
What is the functional group of esters
COO
How are esters formed?
And acid catalyst is usually used
Alcohol + carboxylic acid –> ester + water
Ethanol acid + ethanol–> ethyl ethanoate + water
Methanol + propanoic -> methyl propanoate + water
Advantages of esters
Many esters have pleasant smell of them quite sweet and fruity they are also volatile this makes them ideal for perfume
Esters mix well with alcohol and other organic solvents
What are some disadvantages of esters?
Many esters of flammable third out volatility also make them potentially dangerous
They don’t mix very well with water
When a carboxylic acid reacts with carbonate
what is produced?
Carbon dioxide & water
Eg ethanoic acid + sodium carbonate –>
Carbon dioxide + water + sodium ethanoate
When carboxylic acid dissolves in water to produce acidic solution what happens?
When they dissolve they ionise and release h+ ions which are responsible for making the solution acidic. But because they don’t Ionise completely not many H+ ions are released, Day just for a week acidic solution. This means that they have a higher P Hache so less acidic than Aq solution of strong acids with the same concentration
How old carboxylic acid used in industry?
With longer chains of carbon atoms are used to make soaps and detergents
Carboxylic acid are used in the preparation of esters
What is another term for sodium phosphate?
Washing soda
What is produced in the haver process
What is needed to make ammonia
Ammonia
Nitrogen
Hydrogen
What is the industrial condition of the haber process?
Pressure: 200atmosphere
Temperature : 450*c
Catalyst: iron
What is titration used for?
Titration is used to determine accurately how much alkali is needed to react completely with a known volume of acid
What does the endpoint of titration mean?
This means when the acid base reaction is complete and is neutral
How can you determine the endpoint of the titration
Using a universal indicator
What do u do to test for carbonates
Test to see if carbon dioxide by bubbling it through it through like water
If it is carbon dioxide the limewater turns cloudy
How to test for halides such as chloride, bromide , iodide
Add dilute nitric acid acid followed by silver nitrate solution
Chloride gives a white percipiate of silver chloride
How do you test for sulphate ion
Add dilute HCI followed by barium chloride solution
A whir percipiate of barium sulfatr means the original compound was a sulfate
Describe the process of water treatment from reservoir
The water passes through a mesh screen to remove big bits like twigs
Chemicals are added to make sunbeds and microbes stick together and fall to the bottom
The water is filtered through gravel beds to remove all the solids
Is chlorinated to kill off any harmful microbes left
What is a reversible reaction
Is one where the products of the reaction Can themself react to produce the original reactants
What is the general formula of an alcohol
CnH2n+1OH
The first free alcohols have similar properties
state them
Alcohols are flammable. They burn in the air to produce carbon dioxide and water
The first free alcohol all dissolve completely in water to form neutral solution
They all react with sodium to give hydrogen and Alcoxide e.g. ethanol give sodium if ethoxide and hydrogen
What are the advantages and disadvantages of hydrogen gas being used to burn to power vehicles
Advantages are that hydrogen combined with oxygen in the air to form just water so it is very clean
Disadvantage is that you need special expensive engine and hydrogen is very hard to store
Flame test identifies metal ions
What colour would a lithium ion present
what colour would a potassium ion give off
Serena yelled cats r pests like Lolu calls beamari Google
Sodium yellow calcium red potassium lilac lithium Crimson barium green light
