Flashcards in Chemistry 1 Deck (54):
How will two non-metals react?
They will form a covalent bond by sharing pairs of electrons.
A symbol equation uses element symbols rather than words in an equation.
i.e. H - Hydrogen
How will a metal and a non-metal react?
They will form an ionic bond. The atoms will loose or gain electron forming ions and an electrostatic attraction.
Define element, mixture and compound.
Element contains only one type of atom.
Compound contains more than one type of atom, chemically bonded.
Mixture contains more than one type of atom, not chemically bonded.
What are the Nobel gases?
The noble gases make a group of chemical elements with similar properties: they are all odorless, colourless, gases with extremely low reactivity due to full outer shells.
What are electrons protons and neutrons?
Electrons are found in shells around the nucleus and have negative charge.
Protons are within the nucleus and have a positive charge.
Neutrons are within the nucleus and have no charge.
How do you read the periodic table?
Along the top are groups (how many electrons are in outer shell)
Down the left are periods (number of shells)
How do you find out the number of electrons, protons and neutrons?
Atomic number shows number of protons and electrons.
Relative atomic mass- Atomic Number= neutrons.
How are electrons arranged in shells?
2 in first shell.
8 in the shells after.
What is the principle of the conservation of mass?
The amount of matter involved in a chemical reaction cannot change. The total mass must be the same.
How do you balance Symbol equations?
What is limestone made of?
Limestone is Calcium Carbonate CaCO3
What is thermal decomposition?
Thermolysis is thermal decomposition by heat.
Calcium carbonate -(heat)--> calcium oxide and carbon dioxide.
How do you test for carbon dioxide?
Bubble the gas through limewater. It will turn cloudy and milky white if CO2 is present.
What is the limestone cycle?
Calcium Carbonate (limestone)
Calcium Oxide (quicklime)
Calcium Hydroxide (slaked lime)
Calcium Hydroxide Solution (limewater)
Calcium Carbonate (limestone precipitate)
What are the contents of cement, concrete and mortar?
Cement: limestone, clay and sand
Concrete: cement, water, rock (aggregate) and heat
Mortar: cement and sand
What is produced when metal carbonates react with acid?
Acid+metal carbonate--> salt+water+carbon dioxide.
What is the limestone cycle? (symbol)
What is an ore?
An ore is natural occurring solid material containing metal compounds which are economically viable to extract.
How can metals be extracted by carbon reduction?
Metals found in their oxides and carbon extracts the oxide i.e. copper oxide + carbon -> copper + carbon dioxide
Why is gold a native metal?
It is a metal that can be found in its purist form- the element alone.
Which metals are extracted by electrolysis?
Potassium aluminium calcium magnesium titanium
How can copper be extracted?
Copper can be extracted from its ore by heating with carbon then is purified by electrolysis using a copper electrode
Why is aluminium and titanium expensive to extract?
They must be extracted by electrolysis this requires a lot of energy which is costly. Titanium is also a batch process using other chemicals which can also be expensive.
Why do people research the extraction of copper?
Traditional mining uses huge and opencast mines that produces waste rock and well as often poisoning surrounding water and causing noise pollution
Why should we recycle metals?
Mining for new metals is expensive in ecologically harmful. Metals are easy to recycle with the output of high quality. Metals are also finite resources
What happens in electrolysis?
Ionic substances dissolve in water into seperate ions which conduct electricity. This current causes the ions to seperate to each electrode.
What is an alloy and where is it used?
A mixture of two elements one a metal, making them more useful. The different size atoms to stop the arrangement so layers cannot slide and so making the metal stronger for more use.
What are the properties of transition metals and where are they in the periodic table?
They are all the metals between group 1 and group 3 they form coloured compounds. The are good conductors of heat and electricity. The are shaped easily. They are less reactive than alkalis. They have High melting points. They are hard and tough. And they have a high density.
Why does iron from the blast furnace have Ltd uses?
Pig iron is brittle and is only 96% iron with carbon impurities. This has to be purified and then injected with small amounts of carbon to be of any use.
What is the useful properties of copper?
Copper is soft, is easily shaped, and a good conductor of electricity.
What are the specific useful properties of aluminium and titanium?
They are low-density, light, resist corrosion with a thin layer of oxides.
They are used for cables, aircraft, and hip joints.
Aluminium is weaker than titanium however.
What is an alkane and the general formula?
Alkanes are a family of hydrocarbons that share the same formula.
Alkanes are saturated or single bonded.
What is a hydrocarbon made of?
They are compounds made up of carbon and hydrogen.
What is the formula for methane, ethane, butane and propane?
Methane is CH4.
Ethane is C2H6.
Propane is C3H8.
Butane is C4H10
What are the properties of hydrocarbons?
Made of hydrogen and carbon
Found in crude oil
Short chains: Longer chain:
Good fuels. More viscous
More volatile. Burn less easily
Flammable. Burn to produce particulates
How are hydrocarbons separated into fractions?
The fractionating column separate according to the boiling points. The longer the chain of hydrocarbons; the higher the boiling point. The crude oil is vaporised and condenses at different points up the column as it cools seperating it.
What is complete and incomplete combustion?
Complete combustion occurs when there is plentiful oxygen supplies.
Incomplete combustion happens when there is little or poor oxygen.
What gases are released when a fuel burns?
When a fuel burns completely carbon/nitrogen dioxide, water vapour and particulates are released
When a fuel burns incompletely carbon/nitrogen monoxide, water vapour and particulates are released
What is the environmental effects of sulphur dioxide nitrogen dioxide and solid particles?
They cause acid rain which destroys animals and habitats and makes land in fertile crops to grow.
What are biofuels and their uses?
Biofuel is derived directly from living matter, aims to be carbon neutral, cheaper, and doesn't use resources. However, this can destroy habitats, had a long manufacture process, and displaces food production.
What is cracking?
This is the vaporistaion of long chain hydrocarbons in the presence of a catalyst splitting into shorter chain molecules
Alkanes become Alkenes
What is the formula of Ethene and propene?
Ethene is C2H4.
Propene in C3H6
What is an alkene and its general formula?
Alkanes are unsaturated hydrocarbons. They have a double bond. CnH2n
How to test for unsaturation using bromine?
Unsaturated hydrocarbons turn bromine water from yellow to colourless
What are the uses of polymers?
Some uses in the home include nylon tights, Teflon cookware, liquid absorbing crystals, Styrofoam cups, PET bottles, like the closing fibre, makrolon lenses, hair products and PVC card
How are polymers formed from monomers?
Polymers are chains of monomers. during polymerisation (heat and pressure) the double bonds link chains
Ethene becomes Polyethene
What are the problems of using Polymers?
They are slow to degrade, low flame retardancy, and emits poison gases when burned.
How is ethanol produced?
We can use alkanes to make ethanol.
C6H12O6 -(yeast)-> 2C2H5OH+CO2
Ethene, steam. Phosphoric Acid
What are the advantages and disadvantages of producing ethanol?
Ethene and steam
Is nonrenewable, continuous, steelworkers, fast reaction, high temperature, high pressure, pure, not of energy.
Is renewable, batch, many workers, slow reaction, normal temperature, normal pressure, impure, little energy.
How are plant oils extracted?
The Olive tree close
Olives ground to paste
Paste is pressed
Liquid is squeezed
Skim the oil
Seeds are harvested
These are ground and pressed
Distil if solvents used
Treated to remove impurities
Why are vegetable oils used in cooking?
They provide many nutrients. However excess amounts can cause weight gain. TransFats cause heart disease. Vegetable oils have a higher boiling point and cooks quicker
What is an emulsion and how is it formed?
Emulsions don't dissolve in water heaters water and I'll which would sit on water as it is less dense.
An emulsifier has a hydrophilic end and a hydrophobic end keeping emulsions together