Edexcel Chemistry IGCSE

PAPER CHROMATOGRAPHY - COMPOSITION OF A MIXTURE Diagram Showing the Composition of an Ink using Paper Chromatography COMPOSITION OF A MIXTURE: Chromatograms will Show the Composition of a Mixture as the Different Coloured Substances (Components) will Spread Apart as they will Have Different Solubilities so will Travel at Different Rates A Pure Substance will Only Produce One Spot on the Chromatogram during Paper Chromatography In the Diagram Above, Red, Blue and Yellow are Three Pure Substances, whilst the Sample on the Left is a Mixture of All Three - https://igcse-chemistry-2017.blogspot.ae/search?q=1.11

SIMPLE DISTILLATION Diagram Showing the Simple Distillation of a Mixture of Salt and Water USE: To Separate a Liquid from a Solution (E.g Water from a Solution of Salt Water) EXPLANATION: Solution is Heated and Water Vapours will Rise and Evaporate Water Vapours will Pass through the Condenser, where it Cools and Condenses, turning into a Liquid that will be Collected in a Beaker After All the Water is Evaporated from the Solution, the Solute will be Left Behind FRACTIONAL DISTILLATION Diagram Showing the Fractional Distillation of a Mixture of Ethanol and Water USE: To Separate Two or More Liquids that are Miscible with One Another (E.g Ethanol and Water from a Mixture of the Two) EXPLANATION: Solution is Heated at Temperature of Substance with the Lowest Boiling Point This Substance will Rise and Evaporate, and Vapours will Pass through a Condenser, where it Cools and Condenses, turning into a Liquid that will be Collected in a Bea...

Impure compounds have a range of melting points and boiling points, as the different substances they contain melt or boil at different temperatures. They may even interfere with each other's melting and boiling points.  However, pure compounds have definite melting points and boiling points. The presence of an impurity usually: Lowers the melting point Raises the boiling point The greater the amount of an impurity, the bigger the differences from the true melting point and boiling point. -BBC Bitesize

Element : A substance that cannot be broken down into simpler substances by  chemical means . An  element  is composed of atoms that have the same atomic number. Compound:   A substance formed when two or more  chemical  elements are chemically bonded together. Mixture:   A  mixture  is a combination of two or more pure substances in which each pure substance retains its individual  chemical  properties.

Solvent : The substance that the solute is getting dissolved into which then forms a solution. eg. In brine the solvent is the water Solute:   The   substance that is getting dissolved. eg. In brine the solute is the salt Solution:  The product formed from the reaction. eg. In brine the solution is the brine Saturated solution:   A solution in which no more solute can be dissolved, as it's reached its maximum capacity.

Osmosis : Water particles have   a kinetic energy which allows them to bounce off of each other and mix with the particles of the coloured solution. Eventually the coloured solution will be evenly dispersed  throughout the water, diluting it and making the water turn the colour of the dye. Osmosis is the movement of water from a less concentrated solution to a more concentrated solution through a partially permeable membrane. Diffusion: Gas particles have a high kinetic  energy which allows them to bounce off each other and disperse throughout the air, mixing with other particles. eg. the spreading of the scent of perfume through the air Diffusion is the spreading of particles from an area of high concentration to an area of low concentration.

Solid to Liquid- (melting)   The particles gain kinetic energy and vibrate faster. This allows the particles to overcome the forces of attraction that hold them in place in the solid state.  The regular pattern is broken down and the particles are free to 'slide over' each other. Liquid to Solid- (freezing) The particles lose kinetic energy which then allows the forces of attraction between the particles to hold them together. The particles are arranged in a regular pattern and cannot slide over each other. Liquid to Gas- (boiling) The particles gain kinetic energy and move further apart.  The forces of attraction between the particles are completely destroyed and are then able to escape from the liquid. Gas to Liquid- (condensing)  The particles lose kinetic energy, this allows the forces of attraction to bring the particles closer together.  The particles then cluster together to form a liquid. Solid to ...

Solids Particles touch and vibrate around a fixed point . They are in a fixed neat order . Particles have little energy. Liquids Particles touch . They are in a random order. Particles move over each other but are always touching at least one other particle. Particles have more energy than a solid but less than a gas. Gas Particles are far apart and bounce randomly around the container. Particles are not touching, though they may frequently collide . Particles have a great amount of energy.