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115 Cards in this Set
- Front
- Back
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What is the particle theory? |
- all matter is made of tiny pieces of particles - The particles are arranged differently in a solid, liquid and gas (this is why these states have different properties) |
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Solid Properties |
- Close together - Regular arrangement - Strong forces between particles - Particles vibrate but are unable to move apart - Particles cant move when pressure is applied |
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Liquid Properties |
- Close together - Irregular arrangement - Forces between particles are less strong - Particles move around, slide past each other - Particles cant move when pressure is applied |
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Gas Properties |
- Particles are far apart - Random arrangement - No forces between particles - Particles can move freely and collide - Gas can be pushed into a smaller volume |
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How do we know there are particles, and that they can move? |
Smell Of Cooking - Smell can travel through the area - Smell is due to the gas particles ability to move freely. - The gas particles collide in the air allowing them to travel a further distance |
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What happens when a solid is heated? |
1. The solid is held in a regular structure. Particles do not move. 2. Once heated the particles take in the heat energy and vibrations become stronger 3. As it continues to heat the particles vibrate so much till the structure breaks down (solid to liquid) 4. Particles gain enough energy to escape (evaporation) |
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Change of state graph |
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How is water vapour changed back to ice? |
- Water vapour is cooled below 100 degrees causing condensation to occur - Water then freezes and solidified at 0 degrees |
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What is sublimation |
when you heat some solids, the energy taken in overcomes all forces between particles. The solids go straight from solid to gas. This change is known as sublimation. |
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Brownian motion |
The random movement of particles seen under a microscope. This is caused when particles collide. |
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What is diffusion? |
Process when particles mix and spread through collisions through each other |
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What state does diffusion occur fastest? |
Gases because particles move fastest and more collisirrrrrrrons take place. |
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What increases rate of diffusion? |
- Surface area - Greater concentration difference - Higher temperature |
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Experiment to compare rates of diffusion |
- When the two substances meet it creates a white cloudy substance - It is closer to the right end there for the ammonia solution traveled fastest |
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What does the relative molecular mass have in common with the rate of reaction? |
The Lower the molecular mass the faster the gas will diffuse. |
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Time (Unit, Tool) |
- Seconds - Minutes - Stopclock |
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Mass (Unit, Tool) |
- Grams - Kilograms - Weighing balance |
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Temperature (Unit, Tool) |
- Degrees Celcius - Thernometer |
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Volume Of Liquid (Unit, Tool) |
- Cubic centimetre (cm^3) - Millilitre (ml) - Cubic decimetre (dm^3) - Measuring cylinder - Burette - Pipette |
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A pure substance... |
- has no particles of any other substance mixed with it - Melts and boils at temperatures that are unique to it - Melts exactly to its melting point |
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A impure substance... |
- Has particles of another substance mixed with it - Melts over a range of temperature - Melts at a lower temperature than the pure substance - Boils at a higher temperature than its original substance |
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How can you tell if a substance is pure? |
- Weather or not the melting and boiling point is exact to the original substance |
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Mixture Definition |
Two or more substances that are not chemically combined |
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Solution |
Solution A mixture you make by dissolving a substance in a solvent |
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Solute |
The substance that you dissolve |
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Solvent |
The liquid in which you dissolve the substance |
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Filtration (Seperation |
- The solid remains on the paper - The liquid or filtrate passes through the paper |
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Crystallisation (Seperation) |
- Heat the solution to evaporate some solvent - Test the solution using a glass rod - If crystals form on the rod, the solution is saturated - Separate the crystals by filtering - Wash the crystals with little distilled water |
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Simple Distillation (Seperation) |
- The solvent boils off as a gas, as its boiling point - The gas condenses back to a liquid in the cool condenser - The solute remains in the flask |
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Fractional Distillation (Seperation) |
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Separation of sand and salt |
1. Add water to dissolve salt 2. Filter to remove the sand 3. Sand does not dissolve 4. Evaporate the filtrate to obtain pure salt |
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Separation of Alcohol and water |
Use fractional distillation to distil the alcohol, which boils at a lower temperature than water. |
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Separation of Petroleum from hundreds of other compounds |
Use fractional distillation to separate the compounds into groups, each with quite small range of boiling points. Collect the groups in order of their boiling points |
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Separation of air (gases) |
Cool the air until its liquid, then use fractional distillation to boil the gases off one by one. |
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What is paper Chromatography? |
A way to separate substances from a mixture. - The mixture is dissolved in a suitable solvent - The solution is allowed to travel across paper - The substances in the solution travel at different speeds. So they separate - They separate because of their different solubility in the solvent - The more soluble a substance is the further it will travel |
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What is Chromatography used for? |
- Find how many substances are present in a mixture - To check on the purity of a substance - To identify the substances in a mixture, by measuring how far they travel |
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What are are atoms |
- Elements consist of atoms - atoms are made up of smaller particles: protons, electrons and neutrons - unit = relative atomic mass units |
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Proton (charge and mass) |
- Mass = 1 - Charge = +1 |
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Neutron (charge and mass) |
- Mass = 1 - Charge = 0 |
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Electron (charge and mass) |
- Mass = 1/1840 (almost nothing) - Charge = -1 |
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What does the number of protons tell you? |
What element it belongs to |
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What are isotopes |
An atom with the same number of protons a electrons but a different number of neutrons |
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What are radioactive isotopes |
Isotopes that break down naturally that give out radiation as it decays. |
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Uses for radiation (medical and industrial) |
- Treating cancer cells (cobalt 60 - medical tracers (iodine 131) - tracers to detect leaks in oil and gas pipes - Sterilisation (kill bacteria) |
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Periodic table notes |
- Elements are arranged in order of their proton number - Rows are periods and columns are groups - Period numbers show the number of shells - Group number for 1-7 is the same as the number of outer shell electrons - Outer shell electron dictate how they react - Atoms of group 8 are noble gases |
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What is the difference between atoms and ions? |
Atoms has no charge however ions do so because they have gained or lost electrons. |
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Characteristics of metals |
- Conduct electricity and heat - mostly malleable (hammered into shapes) - ductile (can be drawn into wires) - Tend to be shiny - High density (heavy) - High melting points - Form positive ions in reactions - Form basic oxides |
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Characteristics of Non-Metals |
- Do not conduct electricity or heat - Brittle as a solid (breaks up when hammered) - Look dull as a solid - Low density (light) - Low melting points - Forms negative ions - Form acidic oxides |
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Definition of Metals |
Metals are elements so they contain only one type of atom |
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Definition of Alloys |
Alloys are mixtures, where at least one other substance is added to the metal |
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Examples of alloys |
- Brass (copper, zink) - Stainless steel (iron, Chromium, Nickel) |
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What is a covalent bond? |
- Electrons are shared between atoms - Non metal atoms only - Sharing the electrons creates the bond |
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What is a Ionic bond? |
-Electrons are transferred from one atom to another forming ions - Metals atoms with non metal atoms only - Attraction between ions of opposite charges |
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What is a metallic bond? |
- A lattice of positive ions in a sea of electrons - Only metal atoms - Attraction between positive ions and electrons |
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Why do atoms bond? |
Atoms bond to gain the same arrangement of outer shell electrons as a noble gas to have a stable arrangement. |
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What is a simple molecular structure? |
- A lattice built up by millions of separate molecules - Strong covalent bonds hold it together - Low melting point as it does not take much heat energy to break up the lattice to form a liquid |
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What is a giant structure? |
The lattice is built up of millions of particles which can be: --> Positive and negative ions (ionic) -->Metal ions in a sea of electrons (metallic) --> Non metal atoms (covalent - Particles held together by many strong bonds - High melting point since it takes a great deal of heat energy to break the bonds.w |
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Example of ionic bonfing |
Sodium Chloride - positive sodium ions and negative chloride ions are transferred. - Millions of ions group together to form a lattice |
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What are the properties of ionic compounds? |
- High melting and boiling points - Conduct electricity when melted or dissolved in water because the charged ions are more free - Soluable in water |
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How to write the formula for an ionic compound? |
No chard in a ionic compound. The total positive charge must balance the total negative charge. Just adjust the number of ions in the formula until the total charges on them balance. |
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Structure of simple molecular substances |
- Strong covalent bonds within molecules - Weak attraction between molecules |
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Properties of simple molecular substances |
- Low melting and boiling points as internal forces are weak. - Does not conduct electricity as they have no charge - insoluble in water but soluble in organic solvents |
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Bonding of Diamond |
- carbon atom shares all four of its outer electrons with each other carbon atoms, to form a a three dimensional lattice - Strong covalent bonds - Each carbon atom forms a tetrahedron with four other carbon atoms |
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Properties and uses of Diamond |
- High melting point as bonds are strong - Very hard due to its strong bonds - Cannot conduct electricity as there are no electrons free to move - Insoluble in water - Cutting tools - Jewellery |
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Bonding of graphite |
- A carbon atom shares three of its outer electrons with other carbon atoms to form a layer structure. - The fourth electron exists between the layers and is free to move - Wear forces between layers - Strong covalent bonds in layers (hexagons) |
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Properties and uses of graphite |
- high melting and boiling point as covalent bonds are strong - Soft and slippery due to layers over laping - Good conductor of electricity because of the electrons moving freely - Insoluble in water - Lubricant - Electrodes for electrolysis in labs |
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Silicon dioxide |
- a macromolecular compound - Strong bonds - High melting point and is hard - Bad conductor of electricity and is insoluble in water - Used in sandpaper and to line furnaces |
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Reasons for specific metallic properties |
- High melting points due to strong bonds - Conduct electricity due to free electrons - Malleable (bendable) as layers slide past each other - Ductile for the same reason as above |
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What are organic compounds? |
- Carbon compounds that originate in living things - Always have covalent bonds between carbon atoms in their molecules - Organic compounds that contain only carbon and hydrogen are called hydrocarbons |
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Organic compound examples |
- Methane - Butane - Ethonal |
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What are fossil fuels? |
The remains of living things from millions of years ago. So they are mainly organic compounds. |
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How is petroleum separated? |
- Split up into groups of compounds (molecules of similar size) - It is carried out by fractional distillation - The groups of compounds are called fractions - The separation is carried out in a fractioning tower |
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Refinery Gas Uses |
Bottled gas for heating and cooking |
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Gasoline uses |
Petrol for cars |
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Naphtha uses |
Starting materials for making many chemicals and plastics |
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Kerosene uses |
Fuel for aeroplanes, oil stoves, and oil lamps |
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Diesel oil uses |
Fuel for diesel engines |
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Fuel oil uses |
Fuel for power stations, ships and home heating systems |
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Lubrication fraction uses |
Lubricants for car engines and machinery; waxes and polishes |
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Bitumen uses |
Making roads and covering roofs |
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What is the connection between size of molecules and boiling points? |
- The smallest molecules have the lowest boiling points (most volatile) so evaporation takes place fastest - Compounds with the largest molecules remain a solid - The larger the molecule the less easy it is to burn as a compound so the lowest two fractions are not used as fuels |
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Problems with fossil fuels |
- Carbon dioxide and water vapour is formed when burned. Carbon dioxide traps heat in the atmosphere as it is a green house gas - Produces sulfur dioxide and other pollutants |
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Methane burning formula |
Methane + Oxygen -> Carbon dioxide + Water + energy |
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Periodic table : Groups |
- Elements in a group have same amount of outer electrons therefor they have similar properties - Group number represents the number of outer electrons |
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Periodic table: Periods |
- Along a periodic table the proton numbers in crease by one each time (left to right) - No similar properties in a period |
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Group 1: The six alkali metals |
Lithium, Sodium, Potassium, Rubidium, Caesium, Francium --------> --------> --------> --------> --------> --------> - Softness increases - Density increases - melting and boiling point decrease - Increase in reactivity |
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Properties of alkali metals |
- Much softer - much lighter (low density) - Much lower melting and boiling points - Much more reactive |
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Group 7: The halogens |
Fluorine, Chlorine, Bromine, Iodine, Astatine - Poisonous non metals - Form colourless gases - They exist as diatomic molecules - More reactive than most other non metals |
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What is a conductor? |
Substances that let electricity pass through |
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What is a insulator? |
A substance that does not let electricity pass though |
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How to test if a substance conducts? |
Put it into a circuit (battery, bulb, switch and substance) |
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How does electrolysis work? |
1. Electrons flow from negative to positive 2. IN the electrolyte ions carry charge 3. Electrons flow from anode to the battery 4. electrons are put into cathode forming a substance from the anode 5. Reduction occurs at the cathode and oxidation occurs at the anode |
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What are electrodes made of |
Carbon or platinum as the carry current |
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What is the product of electrolysis? |
Always gives a metal or hydrogen to the cathode and a non metal to the anode |
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Electrolysis Equations |
CATHODE ANODE Lead Bromide --> Lead + Bromide Lead Iodide --> Lead + Iodide Sodium Chloride --> Sodium +Chlorine |
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What is the reactivity series? |
1. Potassium 7. Iron 2. Sodium 8. Lead 3. Calcium 9. Hydrogen 4. Magnesium 10. Copper 5. Aluminium 11. Silver 6. Zinc |
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What is O.I.L R.I.G? |
Oxidation is Loss, Reduction is gain (of electrons) |
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What are half equations used for? |
- Show the reaction at the electrodes - One half shows the loss of electrons and the other shows the gain |
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What is electroplating? |
When a metal is coated with another to protect against corrosion or to make it look more attractive. |
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Examples Of electroplating |
- Steel coated with tin (rust proof) - Steel taps coated with chromium (shiny) |
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How does electroplating work? |
- Metal (coat) on anode - Object (to be coated) on cathode - Same process as electrolysis |
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What does exothermic and endothermic mean? |
Exo means exit so exothermic means energy is given out. Endothermic pulls heat making it colder. |
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Exqmple |
CONTINUEEEEE |
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What are Alkanes? |
Hydrocarbons where each carbon forms 4 single bonds |
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What are Alkenes? |
Hydrocarbons that contain one double bond between carbon atoms |
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What are Alcohols? |
They are alkanes with an OH attached to a carbon attom |
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What are carboxylic acids? |
Same as a alkane but has a carbon atom attached with a double bond to a O and a single bond of OH |
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What compound does 1, 2, 3 and 4 carbon atoms make |
1 = methane 2 = ethane 3 = propane 4 = butane |
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What is the homologous series? |
A family of organic compounds |
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Similarities of homologous series? |
- General formula - Functional group - Chemical properties |
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Differences of homologous series? |
- Chain lengths (length increases by 1 carbon atom at a time) - Physical properties (due to increasing molecular size) |
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Alkanes formula and properties |
- Unreactive - Cn H2n+2 |
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Alkenes formula and properties |
- React with bromine - Cn H2n |
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Alcohols formula and properties |
- React with sodium - Cn H2n+1 OH |
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Carboxylic acids formula and properties |
- Acidic, and neutralised by sodium hydroxide - Cn H2n O2 |
