elements, compounds and mixtures

Question 1

examples of elements?

Answer 1

hydrogen, carbon, oxygen

Question 2

what is an element?

Answer 2

a substance made up of one type of atom

Question 3

examples of compounds?

Answer 3

copper (II) sulphate, calcium carbonate

Question 4

what is a compound?

Answer 4

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

Question 5

examples of mixtures?

Answer 5

air, salt and water

Question 6

what is a mixture?

Answer 6

a combination of 2 or more substances that are not chemically joined together

Question 7

physical test for water?

Answer 7

boils at 100 degrees celsius and freezes at 0 degrees celsius

Question 8

chemical test for water?

Answer 8

turns anhydrous copper sulphate white to blue

Question 9

how to separate a liquid and a soluble solid from a solution?

Answer 9

simple distillation

Question 10

how does simple distillation work?

Answer 10

• the solution is heated and pure water evaporates producing a vapour which rises through the neck of the round bottomed flask
• the vapour passes through a condenser, where it cools and condenses, turning into the pure liquid that is left in the beaker
  -after all the water is evaporated from the solution, only the solid solute will be left behind

Question 11

what is used to separate 2 or more liquids that are miscible with one another?

Answer 11

fractional distillation

Question 12

what is used to separate an undissolved solid from a mixture of solid and liquid/ solution?

Answer 12

filtration

Question 13

what is used to separate a dissolved solid from a solution?( when the solid is more soluble in a hot solvent than a cold solvent)

Answer 13

crystallisation

Question 14

what is used to separate substances that have different solubilities in a solvent?

Answer 14

chromotography

Question 15

how to calculate the RF value?

Answer 15

distance travelled by substance divided by distance travelled by solvent