Chemistry Revision - 1
Particle and Matter
● Particle: an atom, a molecule, or an ion
● Matter: made up of particles which are in continual random direction.
Particle Theory
● Particle affect each other
● Particle of different substance has different size
● Particles are moving all the time
● There are spaces in between
● All matter is made up of particles
Particles in Solid
● Regular repeated arrangement (lattice)
● Tightly packed
● Vibrating about a fixed shape
● Definite shape and volume
● Can’t flow
Particles in Liquid
● Irregular arrangement
● Tightly packed, but there are far enough apart to slide over one another
● Indefinite shape, definite volume (takes the shape of the container)
● Can flow
Particles in Gas
● Irregular arrangement
● Particles are very far apart, move freely
● Indefinite shape, indefinite volume (takes the shape of the container)
● Can be compressed, because it does not have a fixed shape/volume
,Changing State of Matter
● Solid → Liquid: Melting → Heat goes into the liquid as it melts, particles gain
energy, vibrate more, particles expand, attraction force weaken
● Liquid → Solid: Freezing → Heat leaves (taken away from) the liquid as it
freezes, particles lose energy, move slowly, particles contract, attraction
force become stronger
● Liquid → Gas: Boiling → Heat goes into the liquid as it vaporizes, particles gain
energy, move actively and freely, particles expand, attraction force weaken
● Gas → Liquid: Condensation → Heat leaves the gas as it condenses, particles
lose energy, move slowly, particles contract, attraction force become
stronger
● Solid → Gas: Sublimation → Heat goes into the solid as it sublimate, particles
lose energy, vibrate more, particle expand, attraction force weaken
State of matter based upon:
● Energy of the particles (e.g. heat makes the particle more active)
● Particle arrangement
● Distance and force between particles
Diffusion
● Only happen in liquid and gas (particles in solid can’t travel around)
● Particles move in random way
● Particles will mixed up with other different particles, until evenly spread out
● Overall movement: more concentration → less concentration
Experiment- Ammonia and hydrogen chloride
- The concentrated hydrochloric acid and ammonia solution will be placed on the
two end of a sealed tube, with soaked cotton.
- White solid, ammonia chloride will be formed at the place where the two gases
meet.
, - The white solid will be formed near HCl, because particles in ammonia
solution are lighter and they will diffuser quicker
- Ammonia lighter, hydrochloric acid heavier.
Factors Affecting The Rate of Diffusion
● Temperature
- Adding energy to the particles
- The higher the temperature, the faster the particle will diffuse
● Concentration difference
- Higher concentration difference resulting in higher diffusion rate
● Diffusion distance
- Smaller distance result in faster diffusion rate
- Longer distance result in slower diffusion rate (takes longer for particles to travel)
● Diffusing material
- Lighter atoms with travel faster than larger atoms
Brownian Motion
● When particles are in a suspension, they move around
● What we see is particle slide and bump over each other
● The movement of particles is affected by temperature
● Particles in both liquid and gas move randomly → The random motion of
particle is called “Brownian Motion”
● The particle of other substance will be pushed or bumped by the liquid/ gas
particles, causing them to move randomly in different directions.
● Proves the particle theory
, Element, Compound and Mixture
● Element: pure substance that contain only one type of atom, cannot be further
broken down. (e.g. hydrogen, carbon, oxygen)
● Compound: two or more types of atom chemically combined together
(e.g.carbon dioxide, water, glucose)
● Mixture: two or more pure substance, not chemically combined
(e.g. EE,EC,CC → mixture of oil and water)
Physical and Chemical Properties
● Physical properties
- Properties that can be determined without the substance changing into
another substance
- E.g. conductivity, electrical, density
● Chemical properties
- Properties of a substance that may be observed when it undergoes a
chemical change or reaction
- E.g. toxicity, radioactivity, oxidation
Physical change: a change in which no new substance are formed
Chemical change: a change in which one or more new substances are formed
Solution, Solute and Solvent
● Solution → when solid dissolved in a solvent
● Solute → dissolved solid (what is being dissolved)
● Solvent → liquid that dissolves the solid (what is dissolving the solute)
To Determine Purity
● Pure substances have a sharp melting point and boiling point
● Check against data booklet to see the difference between the m.p. and b.p.
● Sharp melting point → if (t2 - t1) is smaller than 0.5°C
● If the substance is impure, melting point will be lower, and the boiling point
will be higher
Impurities: unwanted substance that may affect the purity of the substance
(boiling point, melting point)
Separation Technique
● Filtration
- Apparatus: conical flask, funnel, filter paper
Particle and Matter
● Particle: an atom, a molecule, or an ion
● Matter: made up of particles which are in continual random direction.
Particle Theory
● Particle affect each other
● Particle of different substance has different size
● Particles are moving all the time
● There are spaces in between
● All matter is made up of particles
Particles in Solid
● Regular repeated arrangement (lattice)
● Tightly packed
● Vibrating about a fixed shape
● Definite shape and volume
● Can’t flow
Particles in Liquid
● Irregular arrangement
● Tightly packed, but there are far enough apart to slide over one another
● Indefinite shape, definite volume (takes the shape of the container)
● Can flow
Particles in Gas
● Irregular arrangement
● Particles are very far apart, move freely
● Indefinite shape, indefinite volume (takes the shape of the container)
● Can be compressed, because it does not have a fixed shape/volume
,Changing State of Matter
● Solid → Liquid: Melting → Heat goes into the liquid as it melts, particles gain
energy, vibrate more, particles expand, attraction force weaken
● Liquid → Solid: Freezing → Heat leaves (taken away from) the liquid as it
freezes, particles lose energy, move slowly, particles contract, attraction
force become stronger
● Liquid → Gas: Boiling → Heat goes into the liquid as it vaporizes, particles gain
energy, move actively and freely, particles expand, attraction force weaken
● Gas → Liquid: Condensation → Heat leaves the gas as it condenses, particles
lose energy, move slowly, particles contract, attraction force become
stronger
● Solid → Gas: Sublimation → Heat goes into the solid as it sublimate, particles
lose energy, vibrate more, particle expand, attraction force weaken
State of matter based upon:
● Energy of the particles (e.g. heat makes the particle more active)
● Particle arrangement
● Distance and force between particles
Diffusion
● Only happen in liquid and gas (particles in solid can’t travel around)
● Particles move in random way
● Particles will mixed up with other different particles, until evenly spread out
● Overall movement: more concentration → less concentration
Experiment- Ammonia and hydrogen chloride
- The concentrated hydrochloric acid and ammonia solution will be placed on the
two end of a sealed tube, with soaked cotton.
- White solid, ammonia chloride will be formed at the place where the two gases
meet.
, - The white solid will be formed near HCl, because particles in ammonia
solution are lighter and they will diffuser quicker
- Ammonia lighter, hydrochloric acid heavier.
Factors Affecting The Rate of Diffusion
● Temperature
- Adding energy to the particles
- The higher the temperature, the faster the particle will diffuse
● Concentration difference
- Higher concentration difference resulting in higher diffusion rate
● Diffusion distance
- Smaller distance result in faster diffusion rate
- Longer distance result in slower diffusion rate (takes longer for particles to travel)
● Diffusing material
- Lighter atoms with travel faster than larger atoms
Brownian Motion
● When particles are in a suspension, they move around
● What we see is particle slide and bump over each other
● The movement of particles is affected by temperature
● Particles in both liquid and gas move randomly → The random motion of
particle is called “Brownian Motion”
● The particle of other substance will be pushed or bumped by the liquid/ gas
particles, causing them to move randomly in different directions.
● Proves the particle theory
, Element, Compound and Mixture
● Element: pure substance that contain only one type of atom, cannot be further
broken down. (e.g. hydrogen, carbon, oxygen)
● Compound: two or more types of atom chemically combined together
(e.g.carbon dioxide, water, glucose)
● Mixture: two or more pure substance, not chemically combined
(e.g. EE,EC,CC → mixture of oil and water)
Physical and Chemical Properties
● Physical properties
- Properties that can be determined without the substance changing into
another substance
- E.g. conductivity, electrical, density
● Chemical properties
- Properties of a substance that may be observed when it undergoes a
chemical change or reaction
- E.g. toxicity, radioactivity, oxidation
Physical change: a change in which no new substance are formed
Chemical change: a change in which one or more new substances are formed
Solution, Solute and Solvent
● Solution → when solid dissolved in a solvent
● Solute → dissolved solid (what is being dissolved)
● Solvent → liquid that dissolves the solid (what is dissolving the solute)
To Determine Purity
● Pure substances have a sharp melting point and boiling point
● Check against data booklet to see the difference between the m.p. and b.p.
● Sharp melting point → if (t2 - t1) is smaller than 0.5°C
● If the substance is impure, melting point will be lower, and the boiling point
will be higher
Impurities: unwanted substance that may affect the purity of the substance
(boiling point, melting point)
Separation Technique
● Filtration
- Apparatus: conical flask, funnel, filter paper
