Chemistry EOY revision Wednseday

What is an atom made mostly of

empty space

What is the relative mass and charge for a proton

Mass 1

Charge +1

What is the relative mass and charge for a neutron

Mass 1

charge 0

What is the relative mass and charge for an electron

Mass-1/2000

Charge -1

What does the mass number represent

the number of protons and neutrons in an atom

What does the atomic number represent

Number of protons/electrons

Who made the solid spheres model of the atom

John Dalton

What model did JJ. Thompson make

The plum pudding model

What did rutherford discover about the atom

He discovered the nucleus and that atoms are mostly empty space and have a cloud of electrons

What did Niels Bohr discover

that electron exist on shells, fixed distances apart

What experiment did Rutherford do to find out that atoms are mostly empty space

He shot alpha particles at gold foil and most of the atoms passed through but some reflected

What are isotopes

Isotopes are atoms of a certain element that have the same atomic number but a different mass number. They have more or less neutrons so the charge doesn’t change

What is the relative atomic mass

The weighted mean mass of the isotopes of an element compared with 1/12 of a carbon 12 atom

What equation is used to calculate the relative atomic mass

Relative atomic mass=(MassX%abundance)+(MassX%abundance

Total abundance(usually 100)

What is the maximum number of electrons that can be on shell 1

2

What is the maximum number of electrons that can be on shells 2+

8

What is another name for an electron shell

energy level

How would you show that and element had 2 electrons on the first shell, 8 on the second, and 4 on the third

2.8.4

What is an ion

an electrically charged particle formed when atoms lose or gain electrons

Do non-metals usually lose or gain electrons

They usually gain electrons to form negative ions

Elements in the same group all have what

The same number of electrons on the outer shell. Group number=number of electrons in the outer most shell.

What happens when you are writing complex ions

The number on the top right of the 2 ions cross over and go to the bottom of the other atom

What is the complex ion formula for ammonium

What is the complex ion formula for Phosphate

what is the complex ion formula for Carbonate

What is the complex ion formula for sulphate

What is the complex ion formula for Hydrogen-carbonate

What is the complex ion formula for nitrate

What is the complex ion formula for Hydroxide

What is the complex ion formula for Ethanoate

What is a complex ion

an ion containing more than one type of element

What charge will an ion of an element from group 5 have

-3

What charge will an ion of an element from group 3 have

+3

What charge will an ion of an element from group 1 have

+1

what charge will and ion of an element from group 7 have

-1

What is a cation

A positive ion that is formed when an atom loses an electron

What is an Anion

A negative ion that is formed when an atom gains an electron

What are the proportions of gas in the air

78% hydrogen

21% oxygen

1% trace gases

What is test for hydrogen

Put a lit splint in and if hydrogen is present it will make a squeaky pop

What is the test for oxygen

out a glowing splint in and if it relights then oxygen is present

What is the test for carbon dioxide

Pump through limewater and if there is carbon dioxide it will go cloudy

What is the test for chlorine gas

It will bleach damp blue litmus paper white

What are the 2 way of testing for cations

Flame tests, precipitate reactions

What colour does lithium burn in a flame test

red

What colour does sodium burn in a flame test

Yellow

What colour does potassium burn in a flame test

Lilac

What colour does copper burn in a flame test

Green

What colour does calcium burn in a flame test

Brick red

What is the colour of iron 2 solution and what precipitate is formed when it reacts with sodium hydroxide

The solution is pale green and the precipitate is green/grey

What is the colour of iron 3 solution and what precipitate is formed when it reacts with sodium hydroxide

The solution is yellow and the precipitate is orange/brown

What is the colour of copper solution and what precipitate is formed when it reacts with sodium hydroxide

The solution is blue and the precipitate is blue

What is the colour of magnesium solution and what precipitate is formed when it reacts with sodium hydroxide

The solution is colourless and the precipitate is white

What colour is aluminium solution and what precipitate is formed when it reacts what sodium hydroxide

The solution is colourless and the precipitate is white

What colour is calcium solution ad what precipitate is formed when it reacts with sodium hydroxide

The solution is colourless and the precipitate is white

What is the test and result for the anion of chloride

Add silver nitrate and it will produce milky white precipitate

What is the test and result for the anion of bromide

Add silver nitrate and it will produce a cream precipitate

What is the test and result for the anion of iodide

Add silver nitrate and a yellow precipitate will be produced

What is the test and result for the anion of sulfate

Add Barium chloride and a white precipitate will form

What is the test and result for the anion of carbonate

Add hydrochloric acid and it will create effervesence

What is the difference between evaporation and boiling

Evaporation will only occur on the surface of the liquid whereas boiling occurs over a large mass of the liquid. Evaporation can happen at any temperature but boiling only occurs at the liquids boiling point.

What is diffusion

The movement of particles from an area of high concentration to an area of low concentration.

How does chromatography work

it is used to separate and identify liquids base on there solubility. The water is drawn up by capillary action. When the solvent reaches the ink spots they are dissolved and carried up the paper.

Diagram for chromatography

What is an rf value and how can it be calculated

It is a ratio of the distance travelled by sample to the distance travelled by the solvent.

RF = distance moved by sample/distance moved by solvent

What is qualitative data

Qualitative data is subjective therefor is more likely to cause errors or anomalies. e.g. colours

What is quantitative data

Quantitative data is more accurate and less subjective .e.g .Rf value

What is a formulation

A formulation is a mixture which has been designed as a useful product. This includes fuel, cleaning products and fertilisers

Give a simplified method for separating salt from rock salt

1. Grind the rock salt with a pecil and mortar for 2 minutes to that the salt will dissolve easier.

2. Pour the mixture into a beaker of water and mix it to dissolve smaller salt particles.

3. Then put a filter funnel into a conical flask and fold the filter paper and put it in the funnel.

4. Then pour the salty water, a bit at a time until the liquid has passed through.

5. Then use a Bunsen burner with a heat proof mat and a tripod and gauze. Then pour the liquid into an evaporating basin and place it on the heat proof mat until the water has evaporating leaving salt behind.

What is simple distillation

It is used to separate a liquid from a mixture.

Diagram for simple distillation

What is fractional distillation

Can be used to separate and individually collect liquids from a mixture.

What is pure water

A substance that only contains h2o molecules

What is potable water

Water that is safe to drink

What is fresh water

Water from lakes, rivers, and reservoirs

What is the method for making potable water

1. Choose a source of fresh water

2. Sedimentation allows heavy particles to settle at the bottom. These are removed using wire meshes

3. Passing it through filter beds removes solid particles

4. Sterilize/kill microbes using disingectants.

What does saline mean

contains salt

Process of potable water

What are the benefits and key facts for fresh and ground water

• It is the easiest and cheapest of the 3 main methods of making potable water.

  • It requires filtration and sterilisation.

What are the benefits and key facts of desalination

• It is the hardest and most expensive method

• It involves distillation or using membranes. for example reverse osmosis

  • Both require lots of energy

What are the benefits and key facts of Waste water treatement

• It is moderately cheap and uses less energy

• It involves screening, sedimentation, digestion.

  • Several steps, requires large treatment plant

What was the composition of the early earth atmosphere

4% water vapour

95% carbon dioxide

1% trace gases e.g. nitrogen, ammonia, methane

What is the greenhouse effect

It is a necessary process that maintains a temperature high enough for life.

This is how it works

1. Short wavelength radiation from the sun is absorbed by the planets surface.

2. The surface re-radiates long wavelength radiation back into the atmosphere. This is absorbed by greenhouse gasses, preventing it from escaping.

   1. This process traps heat at the surface of the Earth, rising the average surface temperature.

What are 5 human impacts on the greenhouse effect

• Combustion of fossil fuels releases CO2, increasing carbon emissions

• Deforestation- clearing land, releasing CO2, reducing global photosynthesis

• Mass farming- Use of fuels releasing CO2, cattle farms release methane

• Rice farming- flooded rice paddies released methane from decomposition of organic matter.

  • Landfill-anaerobic fermentation releases methane

What are effects of climate change

• rising average global temperatures

• Melting polar ice caps

• More extreme weather variations in seasonal temperatures

• More extreme weather

• More frequent natural disasters

What is a carbon footprint

The sum of all greenhouse gases emitted by a person, product or industry.

What are natural resources

Resources produced without any human influence and instead grow or form naturally. e.g. water, coal, crude oil, metal ores, wood, agricultural crops, cotton, wool.

What are renewable resources

Resources that can be reformed or replenished over an short time. e.g. wood, cotton, wool. IF used responsibly, we wont run out of these.

What are non-renewable resources

Resources that are used up quicker than they are reformed. e.g. crude oil takes millions of years to be created. At current rates, the will run out soon.

What is sustainability

Using resources to meet our current needs without jeopardizing the needs of the future.

What is an LCA

Life Cycle Assessments assess environmental impacts of products and services that people use in their everyday lives

What are the 5 stages of a life cycle assessment

• Extraction of raw materials. Mining, drilling, deforestation.

• Manufacturing and packaging

• distribution and transport

• useable lifetime

• Disposal. Recycling? Reuse?

What are some limitations of LCAs

• Some impacts are easy to see, such as environmental destruction from mining or carbon emissions. Some however are more difficult to assess. e.g. when impacts become indirect, it becomes difficult to assess where to draw the line.

• It is also difficult to numerically assess some environmental impacts. People will need to make value judgement on the scale and severity of an impact, and this will always be subjective