Chemistry

Ionic:

• Bonds formed between metals and non-metals.
• Form ions by transferring electrons-losing or gaining electrons.
• Metal atoms from positively charged ions (+).
• Non-metals from negitively charged ions (-).
• Opposite charged atoms are attracted to each other - strong force of attraction forms a chemical bond.
• The force that pulls the two atoms together is called 'Electrostatic Force.

They do not conduct electricity when they are a solid, but do once they have overcome the strong electrostatic force that keeps them in a lettice.

Covalent:

• Bonds formed between non metals.
• Sharing electrons between atoms.

• Low melting point and low boiling point because the inter molecular forces are weak and require small amount to break them.
• Does it conduct electricity, because it has no free ions.
• It has no charge as it is stable.

It is 2 or more compounds/eliments that have not been chemically reacted to form bonds.
A mixture can be separated.

• Mostly made off HYDROCARBONs.
• Hydrogen, Group 1, and needs to share its 1 electron.
• Carbon, Group 4, needs 4 electrons to become balanced.
• Hydrocarbons are a covalent bonded.

CH4

The temperature at which the liquid boils or the gas condenses.

The tendency to turn into a glass.

How easy it flows.

How easily it burns.

• When plastic is thrown out it becomes bad for the environment as animals get stuck or eat the plastic, then die. It is also bad for the environment as it is long lasting (100 years) and takes up space.
• It's harder to recycle plastics than paper.

• Ethanol for drinking is made by the fermentation of sugar from plants. Enzymes yeast breaks down the sugar into ethanol and carbon dioxide gas. This can be shown in the word equations.

Sugar-->Ethanol +Carbon Dioxide.

• Ethanol with can be used as a solvent for cleaning and for fuel in cars.
• Ethanol with can be made from Hydration instead of by fermentation. Ethernet is made when hydrocarbons are cracked Ethane gas reacts with steam to make ethanol. A catalyst is used in the reaction. The reaction uses a lot of energy to heat the gasses and generate a high pressure. This reaction is known as hydration and can be shown as a word equation.

Ethan + steam -->ethanol.

Oil and water can't mix, so you form two layers. We call the substances "immiscible".

If you add an emulsifier to a mixture of oil and water, it can force the two hating liquid to mix . You have formed a thick stable emulsion -like ice cream.

To make an emulsion you need
Oil
Water
An emulsifier

• The boiling points of vegetable oils are higher than the boiling point of water. This means that food cooked in oils tastes different to food boiled in water. It also contains more energy.
• The melting points of oils may also be raised by adding hydrogen to their molecules. We call this Harding the oil. The reaction takes place at 60 degrease in the presence of a nickel catalyst. The reaction produces a hydrogenated oil.
• Hydrogenated oils are solids at room temperature. This means that they can be made into spreads to be put on bread. It can be used for cakes, biscuits and pastry.

Acids

Acids are substances which produce H+ ions when we add them to water.

Base

Bases are substances that will neutralise acids.

Alkali

An alkali is a soluble hydroxide. Alkalis produces OH- ions when we add them to water.

PH Scale

We use the Ph scale to see how acidic or alkaline a solution is.

0 - Very Acidic     7 - Neutral     14 - Very Alkaline

Acids and Metals

Acid + Metal ---> a Salt + Hydrogen 

Acid and an Insouable Base    (also known as Neutralisation)

Acid + Base ---> a Salt + Water

Base= metal oxide or metal hydroxide.

Acid

• Hydrochloric = Choride
• Salfuric          = Sulfur
• Nitric              = Nitrate

Elctrolysis is splitting up compounds using electricity.

It uses a pair of oppersitaly charged Electrode in a solutions.

• Positive= Anode
• Negative= Cathode

Use " Dont't P.A.N.I.C"

• P. = Postive
•         is
• A. = Anode
• N. = Negitive
• I.   = Is
• C. = Cathode

What is left is Electrlyte - Ionic liquid or solution that has been brocken down by Electroysis.

Googles - to stop anything from splashing in your eyes.

Clear Desk - so everything is out of the way and is left a flat surface to work on.

Correct Cothing - Correct shoes incase something brakes nothing dangling like ties and hair.

When you raise the temperature of the reaction, the molecules bounce around a lot more, they have more energy. And because they are Bouncing around more, they are more likely to collide with each other. Since they are traveling fast with more energy, and are bouncing around more, increases the chance of them collinding, which means they are more likely to combine. When you are at lower temperature, the molecules are slower and have less energy and have less chance of colliding. Therefore the temperature drop lowers the rate of the reaction.

Rates=

• Speed.

Reaction=

• Enough energy to cause a collision for reactants to react.
• or more reactants Chemically Bonding.

Reactants IN   ----> Products OUT

Minimum amount of energy needed for collision to happen between 2 or more reactants = Activation Energy.

We want to increase the number of collisions between the reactants =

Increase The Frequency of Collision

• Increasing the Temperature - more energy.
• Catalyst - increase the surface area which decrease the activation energy needed for the reaction,
• Consentration - how strong the objects being used are.
• Surface Area - make the substance my exposed by maybe cutting it up into smaller pieces.
• Pressure - same number of particles in a smaller area.

RofR= Amount of Product Made / Time.

RofR= Amount of Reactant Used / Time.

I.V. = Independent Variable = the one you change.

D.V. = Dependent Variable = the one you measure.

C.V. = Controlled Variable = the one that stayes the same for it to be a fair test, so what you need to control and how.

Concentration means how much of an item in a certain area. By adding more of that item can speed up a reaction. This is because there is a greater chance that the molecules will collide, as it is like increasing the amount of people using a corridor at one time, it makes it very hard for hem not to hit each other, and because of this will speed up the rate of the reaction. If there is less of something, there will be fewever collisions and the reaction will probably happen at a slower speed.

Exothermic Reactions=

Exothermic reactions transfer energy to the surroundings.

Endothermic Reaction=

These are reactions that take in energy from the surrounding. (surroundings become colder).

A Reversible Reaction =

Is a reaction that occurs in both the forward and reverse direction.

(Energy Can Not Be Created Or Distroyed)

The amount of energy released in one direction in one direction must be the same as the energy absorbed in the opposite direction.

This is the spperation of colours.

(1) - Draw a pencil line 1cm up from the bottem of your chromatograph paper. This is the base line.

(2) - Spot one of the different inks along the baseline.

(3) - Secure the paper from the top and dip into your solvent. Make sure the solvent does not go above the base line.

(4) - Allow the sovlvent from (mobile phase), to travel up the paper (stationary phase). When it is 1cm from the top, remove the paper and alow to dry.

(5) - Use a pencil to draw around any marks on the paper and stick on your page.

(6) - Conclude which colours the coloured ink is made from.

Empirical Formular =

Gives the simplest possible whole number ratio of attoms of each element within a compound.

Ar = Atomic Mass.

The early atmosphere:

• Carbon Dioxide = 92%
• Nirtrogen            = 4%
• Methane              = 2%
• Ammonia            = 2%

The modern atmosphere:

• Nitrogen            = 78%
• Oxygen              = 21%
• other-Argon, Carbon Diocxide, =1%