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Edexcel GCSE Chemistry COPY > Paper 1 Collection ✓ > Flashcards

Flashcards in Paper 1 Collection ✓ Deck (195)
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1

SC1a - What are the arrangements of particles in each of the three states?

  • Solid: Regular and close together
  • Liquid: Random and close together
  • Gas: Random and far apart

2

SC1a - What are the movements of particles in each of the three states?

  • Solid: Vibrate around a fixed position
  • Liquid: Move around each other
  • Gas: Fast in all directions

3

SC1a - What are the names of the two state changes between solid and liquid?

  • S→ L is Melting
  • L → S is Freezing

4

SC1a - What are the names of the two state changes between liquid and gas?

  • L→ G Evaporating (and Boiling)
  • G → L Condensing

5

SC1a - What are the names of the two state changes between Gas and Solid?

  • G → S Deposition
  • S → G Sublimation
  • During these processes they do not become liquid

6

SC1a - What is overcome during melting and boiling?

Forces of attraction between particles

7

SC1a - In a heating curve, at which points will the line be flat?

During Melting and Boiling [phase changes] as the temperature doesn't increase while the forces of attraction are overcome.

8

SC2a - What are the two key features of a pure substance?

The composition:

  • Cannot be changed by physical means
  • Is the same in all parts of a piece of the substance

9

SC2a - What is a mixture?

  • A mixture contains multiple elements/compounds that aren't chamically joined together.
  • The composition cannot be changed and so it isnt a pure substance.

10

SC2a - How will the heating curve of a mixture look different to a pure substance and why?

  • Instead of straight lines there will be curves.
  • This is because there are multiple different elements which will have different melting points.

11

SC2b - What is filtration?

Using a filter to trap larger insoluble substances from a mixture.

12

SC2b - What is cystallisation?

  • When a solution is evapourated, meaning that the solvent turns to gas leaving behind the solute which forms crystals.
  • The size of these crystals depend on the time the crystallisation takes
  • (Longer time taken = larger crystals)

13

SC2b - What is a saturated solution and how can this be changed?

  • A saturated solution is a solution in which a solvent contains the highest amount of dissolved solute as possible.
  • This limit can be increased by increasing the temperature.

14

SC2b - Descirbe what a risk assesment is and how it is used when crystallising in a lab.

  • Identifying and evaluating the hazards and considering ways of reducing the risk of harmful effects.
  • In crystallisation this would be indentifying:
    •  The solution can spit: wearing eye protection and removing from the bunsen burner before the solution is completely evapourated
    • You can get burnt from the bunsen burner: keep your hands away from the flames at all times

15

SC2c - What is paper chromotography?

  • A method of speration that involves having a piece of paper with dots of ink slightly dipped in the water (so that the water doesnt reach the pencil line that the ink is one).
  • The solvent is called the mobile phase and the paper contains the stationary phase.
  • If an ink moves less up the page it is less attracted to the stationary phase.
  • Different inks have different levels of attraction to the stationary phase and so will get sperated out at different distances.

16

SC2c - How do you measure the Rƒ value of an ink?

Rƒ = Distance travelled by spot ÷ Total distance travelled by solvent

17

SC2c - What can paper chromotography be used for?

  • Distinguishing between pure/impure substances
  • Identifying substances by comparing their chromotogram with known substances
  • Identifying substances by calculating their Rƒ value

18

SC2d - What is simple distillation?

The separation of a liquid from its dissloved solids, by evapourating it and condensing the gas formed.

19

SC2d - What conditions do the components of the solution have to meet for simple distillation to work?

They have to have boiling points that are at least 25° C apart.

20

SC2d - Describe a simple distillation set-up.

  • A side-arm flask on a tripod over a bunsen burner.
  • It contains the solution and anti-bumping granules to help the liquid boil more smoothly.
  • A thermometer is connected to the top.
  • A delivery tube, leading to a conical flask, is surrounded with a cooling jacket (condenser) which takes cold water in from the bottom and puts it out at the top.
  • The conical flask is in a bath of ice water.
  • The bunsen burner is on a heat resistant mat.

21

SC2d CP - Which two methods can you use to seperate solvents in an ink?

  • Paper chromotography
  • Simple distillation

22

SC2e - Why can't water be purified by distillation on a large scale?

It takes up too much energy.

23

SC2e - Why can't tap water be used for chemical analysis?

Tap water contains small amounts of dissolved salts and minerals which may react and alter the resuslts

24

SC2e - Describe the stages river water goes through before it can be used in homes.

  • First, it is screened with a seive to get rid of large objects such as leaves and twigs
  • It is then sent to a sedimentation tank where small particles will settle out at the bottom
  • The water is then filtered through layers of sand and gravel
  • Finally it is treated with chlorine to kill microbes

25

SC3a - Name the three base rules of atomic theory.

  • All matter is made up of atoms
  • Atoms cannot be broken down into smaller parts
  • Atoms cannot be created or destroyed

26

SC3a - Names the three subatomic particles as well as their relative mass and charge.

  • Protons:
    • M: 1
    • C +1
  • Neutron:
    • M: 1
    • C Neutral (0)
  • Electron:
    • M: 1/1835 (negligible)
    • C -1

27

SC3a - Describe the structure of an atom

  • Protons and neutrons centred in a nucleus.
  • Electrons orbiting outside in electron shells.

28

SC3b - What did the Rutherford Gold foil test reveal about the space inside atoms?

Atoms are mostly empty spcae

29

SC3b - What is an atomic number?

The number of protons in an atom. the bottom number on the symbol for an element

30

SC3b - What is a mass number?

  • The number of protons + neutrons in an atom (the mass).
  • The top number on the symbol for an element.