Removes shenanigans

Question 1

atom

Answer 1

the smallest particle of a chemical element that can exist

Question 2

molcule

Answer 2

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Question 3

element

Answer 3

something which consists of one type of atom only

Question 4

compound

Answer 4

a substance made up of two or more different elements which are chemically bonded together

Question 5

mixture

Answer 5

no chemical bond between particles

parts can be separated out only using physical methods

Question 6

what is sublimation?

Answer 6

solid turns straight to a gas

Question 7

experiment to see diffusion using potassium manganate

Answer 7

take a beaker of water and place some potassium manganate at the bottom, the purple colour slowly spreads out to fill the beaker

Question 8

potassium manganate and dilution

Answer 8

if you were to add more water to the final purple solution, the potassium managante particles would spread even further apart and the solution would be less purple, this is dilution.

Question 9

amonia and hyrogen chloride used to demonstrate diffusion

Answer 9

1) aqueos ammonia gives off ammonia gas, hcl gives off hydrogen chloride gas
2) when you set up an experiment with a test tube and two cotton things at the end, you’ll get a white ring of ammonium chloride forming in the glass tube
3) The NH3 gas diffuses from one end of the tube and the hcl gas diffuses from the other, when they meet, they react to form ammonium chloride
4) the ring forms nearest to the hcl as the particles of ammonia are smaller and lighter than the particles of hydrogen chloride, so they diffuse through the air more quickly

Question 10

using bromine gas and air to demonstate diffusion

Answer 10

1) fill half a gas jar full of bromine gas, and the other half full of air. Separate these gases with a gas plate
2) when you remove the gas plate, you’ll see the brown bromine gas slowly diffusing through the air
3) the random motion of the particles means that the bromine will eventually diffuse right through the air

Question 11

about bromine gas

Answer 11

it is brown and strongly smelling

Question 12

filtration

Answer 12

used to separate an insoluble solid from a liquid

Question 13

crystallisation

Answer 13

used to separate a soluble solid from a solution

1) pour the solution into an evaporating dish
2) slowly heat the solution, some of the solvent will evaporate and the solution will get more concentrated. Stop heating when crystals begin to form
3) Remove the dish from the heat and leave it in a warm place for the rest of the solvent to slowly evaporatte
4) finally, you must dry the product using a drying oven or a desiccator

Question 14

separating rock salts (sand and salt)

Answer 14

1) grind up the rock salt with a pestle and mortar
2) dissolve in beaker and stir
3) filter through filter paper in a fuel
4) evaporate in an evaportaing dish

Question 15

chromotography

Answer 15

used to separate dyes

1) draw a line near the bottom of a sheet of filter paper using a pencil as it won’t react with the solvent
2) add spots of different dyes to the line at regular intervals
3) loosely roll the sheet up and put it in a beaker of solvent such as water
4) make sure the dyes aren’t touching the solvent
5) place a lid on top of the container so the solvent doesn’t evaporate
6) the solvent seeps up the paper, the end result is a pattern of spots called a chromatogram

Question 16

simple distillation

Answer 16

used to separate out a liquid from a solution

1) the solution s heated. The part of the solution that has the lowest bp evaporates
2) the vapour is then cooled, condenses (turns back into a liquid) and is collected
3) the rest of the solution is left behind in the flask

example- pure water from sea water

Question 17

disadvantages of simple distillation

Answer 17

you can only use it to separate things with very different boiling points

Question 18

why use distilled water

Answer 18

there are no impurities like ions that might interfere with experimental results

Question 19

fractional distillation

Answer 19

separate a mixture of liquids

1) put your mixture in a flask and stick a fractioning column on top, then heat it
2) the diff liquids will have diff boiling pints so will evaporate at diff temps
3) the liquid with the lowest bp evaporates first
4) liquids with higher boiling points may also start to evaporate, however the column is cooler at the top, so they will only get part the way up before condensing and running back down towards the flask
5) when the first liquid has been collected, you raise the temp until the next one reaches the top