C1 - Carbon Chemistry Flashcards
C1 - Carbon Chemistry
What is a colloid (paint)?
Tiny particles of pigment are dispersed in a liquid. Particles are too small to settle out. Suspended but not dissolved.
C1 - Carbon Chemistry
What does volatile mean?
How easily a liquid evaporates. Particles move faster when heated. Fast moving particles at surface overcome forces of attraction from other particles - evaporate.
C1 - Carbon Chemistry
What is the process called for making an Ester?
Esterification
C1 - Carbon Chemistry
What is the equation for making an ester?
Acid + Alcohol → Ester + Water
C1 - Carbon Chemistry
What is a carboxylic acid?
An acid built around 1 or more carbon atom.
C1 - Carbon Chemistry
Give a method to create an ester…
Mix 10cm³ of ethanoic acid with 10cm³ of ethanol. Add 1cm³ of concentrated sulphuric acid - warm gently. Tip mixture into 150cm³ of sodium carbonate solution - to neutralise. Smell.
C1 - Carbon Chemistry
How can cosmetics be tested?
On animals. Banned in EU and controversial. Some say animals suffer, others say it’s worth checking they won’t harm humans.
C1 - Carbon Chemistry
What is the symbol equation for thermal decomposition of baking powder?
2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O
C1 - Carbon Chemistry
What are synthetic esters/perfumes?
Esters manufactured to use as flavourings or perfumes. E.g. Combinations of esters that smell of lavender, orange, cinnamon.
C1 - Carbon Chemistry
What is the word equation for thermal decomposition of baking powder?
sodium hydrogencarbonate → sodium carbonate + carbon dioxide + water
C1 - Carbon Chemistry
What is thermal decomposition?
When a substance is broken down into simpler substances by heat. Many reactions use a catalyst.
C1 - Carbon Chemistry
Why must potatoes be cooked?
Humans can’t digest cellulose (rigid cell wall). Cooking ruptures cell walls and makes strach cells swell up and spread out. Makes potato softer, more flexible, easier to digest.
C1 - Carbon Chemistry
What happens to proteins when cooked?
They change shape. Energy from cooking breaks some chemical bonds allowing protein to take a different shape. Gives food an edible texture and is irreversible - called denaturing.
C1 - Carbon Chemistry
Why is cooking a chemical change?
Because cooking produces a new substance which can’t be changed back. It is irreversible.
C1 - Carbon Chemistry
What does hydrophobic mean?
Doesn’t like water. Hydrophobic part bonds to oil molecules.
C1 - Carbon Chemistry
What does hydrophilic mean?
Water loving. Hydrophilic part bonds to water molecules.
C1 - Carbon Chemistry
What are anti-oxidants?
They help to preserve food
C1 - Carbon Chemistry
What is a solution?
A mixture of a solute and a solvent that does not separate out.
C1 - Carbon Chemistry
What is an emulsifier and what does it do?
Help oil and water bind together and stop them separating out. Has two parts - a hydrophobic and hydrophilic part.
C1 - Carbon Chemistry
What are food additives?
They are added to food to make them last longer, taste better and look better.
C1 - Carbon Chemistry
What are flavour enhancers?
Bring out taste and smell of a food without adding any flavour of their own.
C1 - Carbon Chemistry
What is a solute?
Substance which is being dissolved.
C1 - Carbon Chemistry
What is a solvent?
The liquid the solute is being dissolved in.
C1 - Carbon Chemistry
What does soluble mean?
It will dissolve
C1 - Carbon Chemistry
What does insoluble mean?
It won’t dissolve
C1 - Carbon Chemistry
What is solubility?
A measure of how much something will dissolve.
C1 - Carbon Chemistry
What can nail varnish also be known as?
Acetone or propanone
C1 - Carbon Chemistry
What is in a paint?
A solvent, binding medium and pigment.
C1 - Carbon Chemistry
What is the solvent for in a paint?
It evaporates when paint dries. Added to make paint thinner and spread easily.
C1 - Carbon Chemistry
What is the pigment for in a paint?
To give the paint its colour
C1 - Carbon Chemistry
What is the binding medium in paint?
It is a liquid that carries the pigment bits and holds them together. When it goes solid, it sticks the pigment to the surface.
C1 - Carbon Chemistry
What are thermochromic pigments and what are they used for?
They are pigments which change colour or become transparent when the temperature changes. They can be used in baby products and kettles.
C1 - Carbon Chemistry
What are thermochromic pigments and what are they used for?
They are pigments which change colour or become transparent when the temperature changes. They can be used in baby products and kettles.
C1 - Carbon Chemistry
What are phosphorescent pigments and what can they be used for?
They absorb light, store it and release it over a period of time. Glow in the dark hands on clocks are safer than radioactive watches.
C1 - Carbon Chemistry
How are polymers formed?
By joining lots of monomers together in a reaction called polymerisation.
C1 - Carbon Chemistry
What conditions are needed for polymerisation?
High pressure and a catalyst
C1 - Carbon Chemistry
What are unsaturated compounds?
Molecules with at least one double covalent bond between carbon atoms.
C1 - Carbon Chemistry
What is addition polymerisation?
Lots of unsaturated monomer molecules (alkenes) can open up their double covalent bond and join together to form polymer chains.
C1 - Carbon Chemistry
What are the properties of a polymer with weak intermolecular forces?
The chains are free to slide over each other which makes the polymer easily stretchable and gives it a low melting point.
C1 - Carbon Chemistry
What are the properties of a polymer with strong intermolecular forces?
They have higher melting points and are rigid, so can’t be stretched because the cross links holds the chains firmly together.
C1 - Carbon Chemistry
What can strong and rigid polymers be used for?
Plastic milk bottles (e.g. high density Polyethene can be used).
C1 - Carbon Chemistry
What can light and stretchable polymers be used for?
E.g. Light density polyethene can be used for plastic bags and squeezy bottles - it’s not good for anything that will get hot because of its low melting point.
C1 - Carbon Chemistry
What uses does PVC have?
It is strong and durable, and can be made rigid or stretchy. The rigid PVC can make window frames and piping. The stretchy can make synthetic leather.
C1 - Carbon Chemistry
What can polystyrene foam be used for?
Packaging and disposable coffee cups because the trapped air makes a good thermal insulator.
C1 - Carbon Chemistry
What is the problem with synthetic fibres?
Nylon coated with polyurethane doesn’t let water vapour through - which means sweat condenses and makes the person uncomfortable. Not breathable
C1 - Carbon Chemistry
What is good about Gore-Tex?
It combines nylon and polyurethane whilst also being breathable. The PTFE film allows water vapout through but stops rain droplets.
C1 - Carbon Chemistry
What are the issues with polymers?
Most aren’t biodegradable - waste land and plastic in landfills. Burning them release toxic gases such as sulfur dioxide, hydrogen chloride, and hydrogen cyanide. Recycling is the best but can be expensive.
C1 - Carbon Chemistry
What is a hydrocarbon?
Any compound that is made up of carbon and hydrogen atoms only.
C1 - Carbon Chemistry
What are hydrocarbons held together by?
Strong covalent bonds between the atoms.
C1 - Carbon Chemistry
What bond do alkanes have?
Single covalent bonds
C1 - Carbon Chemistry
What bond do alkenes have?
Double covalent bonds
C1 - Carbon Chemistry
What are saturated compounds?
(Alkanes) only contain single covalent bonds so they cannot join on to any other atoms.
C1 - Carbon Chemistry
What are the first four alkanes?
Methane, ethane, propane, and butane.
C1 - Carbon Chemistry
What are the first three alkenes?
Ethene, propene, and butene.
C1 - Carbon Chemistry
What does bromine water test for?
The orange liquid turns colourless if an alkene is present because the bromine will be added to the double bond making it a dibromo compound in an addition reaction.
C1 - Carbon Chemistry
How is crude oil separated?
Through fractional distillation. Oil is heated until most is gas. This goes to a fractionating column which has a temperature gradient.
C1 - Carbon Chemistry
Which is the hottest part of a fractionating colum?
The bottom
C1 - Carbon Chemistry
Which is the coolest part of a fractionating colum?
The top
C1 - Carbon Chemistry
Which 3 fractions are at the top of the fractionating column?
LPG, followed by Petrol and Naphtha or Kerosene.
C1 - Carbon Chemistry
Which 3 fractions are at the bottom of the fractionating column?
Bitumen and above that is oil, and then diesel.
C1 - Carbon Chemistry
What happens as the size of the hydrocarbon molecule increases?
The boiling point increases, it gets less flammable, it gets more viscous (doesn’t easily flow) and it gets less volatile.
C1 - Carbon Chemistry
What is cracking?
Splitting up long chain hydrocarbons into smaller, more useful ones.
C1 - Carbon Chemistry
What is cracking a form of?
Thermal decomposition
C1 - Carbon Chemistry
Why are longer hydrocarbons cracked?
Because there is a higher demand for them. Also it produces lots of alkenes which are used to make polymers.
C1 - Carbon Chemistry
What conditions are needed for cracking?
A powdered catalyst (aluminium oxide) at a temperature of about 400°C-700°C
C1 - Carbon Chemistry
What are the environmental problems of oil?
Oil tanker crashes/oil rig problems can lead to oil slicks. If oil covers birds’ feathers it stops them being waterproof so they die of cold/can no longer fly. Detergents can break up oil slicks but can be harmful to wildlife.
