BITS THAT FALL OUT OF YOUR HEAD Flashcards
How to prepare an Insoluble Salt? (In this Case Lead Sulfate)?
- Add 1 Spatula of Lead Nitrate to a test tube.
- Add Water to dissolve it (Deionised water to make sure there are no other ions about)
- Shake it Thoroughly to ensure all the Lead Nitrate has dissolved
- Do the same with 1 spatula of Magnesium Sulfate in another Test tube
- Tip the two solutions into a small beaker, and give it a good stir to make sure it’s all mixed together. The Lead Sulfate should precipitate
- Put a folded piece of filter paper into a filter funnel and stick the funnel into a conical flask
- Pour the contents of the beaker into the middle of the filter
Make sure the solution doesn’t go above the filter paper-otherwise some of the solid could dribble down
the side
- Swill out the Beaker with more deionised water, and tip this into the filter paper- to make sure you get all the precipitate from the beaker
- Rinse the contents of the filter paper with deionised water to make sure that all the soluble magnesium nitrate has been washed away
- Then just scrape the Lead onto fresh filter paper and leave it to dry in an oven
What are the two ways to make a soluble salt?
React an acid with an excess of a solid metal, metal oxide, hydroxide or carbonate
Titration method
How would you tell when to use which method of making soluble salts?
If it is Na, K or Ammonium Salt
Then use Titration Method
How to make Copper (II) Sulfate Crystals?
-Heat acid in a water bath -speeds up the reaction between the acid and the insoluble base.
Do this in a fume cupboard to avoid releasing acid fumes into the room
-Then add the base to the acid - the base and acid will
react to produce a soluble salt (and water).
You will know when the base is in excess and all the acid has been neutralised because the excess solid will just sink to the bottom of the flask
Filter off the excess solid to get a solution containing only salt and water
Heat the solution gently, using a Bunsen Burner, to slowly evaporate off some of the water.
Leave the solution to cool and allow the salt to crystallise.
Filter off the solid salt and leave it to dry
Which Chlorides are insoluble or soluble?
Lead and Silver are Insoluble
Which Sulfates are Insoluble or Soluble?
Barium and Lead (Insoluble)
Silver and Calcium (Insoluble)
Which Carbonates are Insoluble or soluble ?
Sodium, Potassium and Ammonium ones (Insoluble)
Which Hydroxides are insoluble or soluble?
Sodium, Potassium and Calcium ones (Soluble)
Which Nitrates are Insoluble?
NONE
What does it mean by Saturated?
an organic molecule in which all the covalent bonds between carbon atoms are single bonds
What is an Alloy?
Mixture of a metal with, usually , other metals or carbon
If you start with Potassium Bromide (KBr (aq) colourless) and add Cl2 water what will you observe
Orange Solution (Br2)
If you start with KI (aq) and add Cl2 water, what will you observe?
Brown
If you start with KI and add Br2 water, what will you observe?
Brown
Acid + Metal + Carbonate
Salt + Water + Hydrogen
How do you test for carbonates?
.You need to react Hcl or any acid to the Carbonate
.Then you can test for Co2 (If limewater turns cloudy in the presence of Co2)
As 2Hcl + Co3 –> Co2 + H2O
How do you test for Sulfates?
We test for sulfates using Hydrochloric Acid and Barium Chloride (Barium Chloride is more important).
We should then get Barium Sulfate which forms a white precipitate which tells that sulfate is present.
XSo4 (2-) + BaCl2 –> BaSO4
How do you test for Halide Anions?
You must add (Nitric acid and Silver Nitrate to the Halide anion). The Silver Nitrate (AgNo3) then disperses which allows Silver to react with the Halide anion. If this performs a precipitate colour according to the certain halide anion, it is an anion.
What colour should Agcl turn in a Halide anion test?
White Precipitate
What colour should AgBr turn in a Halide anion test?
Creamy Precipitate
What colour should AgI turn in a Halide anion test?
Yellow Precipitate
What colours should form when Sodium Hydroxide reacts with Metal ions?
CuOH –> Blue Precipitate
Fe 2+ (OH)-2 –> Sludgy green precipitate
Fe 3+ (OH)-3 –> Red/Brown
How to test for Ammonium Ions?
Ammonia - NH3, meaning that N needs 3 electrons to become N3-. When Ammonium combines with another H it becomes an Ammonium Ion (NH4+). To detect for ammonium compounds, you nust react it with NaOH, This produces Ammonia (gas) meaning that it is an alkali. The we can test for Alkalis using Litmus paper which should be blue.
What Observations can you make Sodium reacts on water?
Floats because it is less dense than water
Sodium melts into a ball because its melting point is low and a lot of heat is produced by the reaction
There is Fizzing because Hydrogen Gas is produced
Moves around
Smaller
UI turns blue
What happens when Lithium reacts with Water?
Fizzing
Moves around
Smaller
UI turns blue
Floats
Slower than Sodium
What happens when Potassium Reacts with Water?
Enough heat is produced to ignite the Hyrdogen, whcih burns with a lilac flame.
Spitting and exploding
Moves
Smaller
What are the colours of Group 7 Halogens at room temperature?
F2 - Yellow Gas
Cl2 - Green Gas
Br2 - Red-Brown Liquid (Orange Brown Vapour)
I2 - Grey Solid (Purple Vapour)
What is Polymerisation?
The joining up of lots of little molecules (monomers) to make one big molecule (polymer).
What is Addition Polymerisation?
When Molecules simply add onto each other without anything else being formed
What is the use Poly(ethene)?
Low Density - Thin film to make Polythene Bags
(Flexible and not very strong)
High Density- Plastic Bottles and Milk bottles
Uses of Poly(Propene)?
Makes Ropes and Crates
Uses of Poly(Chloroethene)?
(PVC)
Used for water pipes or replacement windows
Can be made flexible by adding plasticisers
Useful for sheet floor coverings, and even clothing.
Can be used for electrical insulation as they don’t conduct electricity
Uses of Polytetrafluoroethene?
Often used as a non-stick coating for pots and pans because it is very unreactive due to the strong carbon-fluorine bonds, and can be found lining containers for corrosive chemicals.
Advantages of Using Landfills to remove plastics?
No greenhouse gases or toxic gases produced from plastics
Cheap
Disadvantages of using Landfills to remove plastics?
Ugly, Smelly and noisy; no one wants to live next to a landfill site
Uses large areas of land
Will be there for thousands of years
Advantages of using Incineration as a method of removing Addition Polymers
Requires little space
Can produce for local homes and/or produce electricity
Disadvantages of using Incineration as a method of removing Addition Polymers?
Expensive to build and maintain
Produces greenhouse gases
Releases Toxic Gases
The ash produced must still be disposed of in landfill sites
Two methods of Producing Ethanol?
Fermentation
Hydration of Ethene
What conditions are required for the Hydration of Ethene?
Starting Matierals: Ethene and Steam
Temperature: 300 C’
Pressure: 60-70 atmospheres
Catalysts: Phosphoric Acid
What conditions are required for the Hydration of Ethene?
Starting Matierals: Ethene and Steam
Temperature: 300 C’
Pressure: 60-70 atmospheres
Catalysts: Phosphoric Acid
Efficient and Quick Reaction Process.
Produces much purer Ethanol but uses high temp and pressures which require a high input of energy
What conditions are required for Fermentation?
Starting Matierals: Glucose
Temp: 30 C’
Catalyst: Enzymes in yeast
Other Conditions: Anaerobic
Slow, inefficent and produces very impure ethanol which needs further processing
Are the Common Salts of Sodium, Potassium and Ammonium Soluble or Insoluble?
Soluble
Why does Ammonia travel faster than HCl?
Lower Molar mass
Two observations when Magnesium reacts with O2?
White Solid
bright / white / blinding AND flame / light
Is magnesium oxide a basic oxide or an acidic oxide?
Basic oxide formed from a non-metal
Definition of Bioddegrade?
(polymer) breaks down / decomposes /
decays
M2 by bacteria / microbes / microorganisms /
decomposers /enzymes
In a Typical Fractionating column? How does the colour, boiling point and visocity differ in the fractionating column?
The bottom of the fraction has the larger crude oil chainlengths
Larger fractions of crude oil
.have higher boiling points
.are darker (in colour)
.have higher viscosities / are
more viscous
What are the Fractions of Hydrocarbons from small to big? and Uses?
Refinery Gases - Bottled Gas Gasoline - Cars Kerosene - Jet Fuel Diesel - Lorries Fuel Oil- Ships Bitumen - Roads
Fuel + Oxygen
Fuel + Oxygen –> Carbon Dioxide + Water
Is a positive Delta H endothermic or exothermic?
Endothermic
What happens when Alcohols are Oxidised?
Turn into Carboxylic acids
Conditions:
Potassium (VII) Dichromate in Sulfuric Acid is the Oxidising agent needed for this reaction.
Heat the ethanol with potassium dichromate in sulfuric acid –> Ethanoic acid
What do Some Microorganisms use as an energy resource for the oxidation of alcohol?
Can use microbes as an energy resource
Carry out aerobic respiration
Use O2 from open air to oxidise to the alcohol
