states of matter and seperation techniques

Question 1

what happens when the energy of a solid increases?

Answer 1

substances melt and boil, for the attractive forces must be broken

Question 2

what happens when the energy of a particle decreases?

Answer 2

substance will condense, then freeze/solidify

Question 3

when do gas pressures increase?

Answer 3

increase temperature and compressiom

Question 4

what happens when gas temperature increases?

Answer 4

particles move faster as they have more kinetic energy and hit the walls of a container more often and with more force, therefore more collision takes place

Question 5

what happens when gases are compressed?

Answer 5

particles are pushed into a smaller space so they hit the walls more often therefore more collision takes place

Question 6

why do gases and liquids diffuse?

Answer 6

because particles move from a high concentration to a low concentration

Question 7

what factors effect diffusion?

Answer 7

• lower particle mass = faster diffusion
• higher temperatures (faster particles) cause faster diffusion

Question 8

molecular mass calculation?

Answer 8

sum of all the mass numbers present in a molecule

Question 9

Rf Value formula?

Answer 9

distance travelled by solute/distance travelled by solution

Question 10

why may a chromatography experiment be unsuccessful?

Answer 10

• colourless solute components
• components don’t move from base line
  -components leave mark at the same area

Question 11

impurity?

Answer 11

• melting point falls
• boiling point increases
• m.p and b.p are no longer sharp

Question 12

purity?

Answer 12

• definite sharp m.p and b.p
• unique pair of m.p and b.p

Question 13

distillation

Answer 13

separates 2 miscible liquids. solution gets headed and the substance with the lowest boiling point vaporises and rises into the condenser, cold water runs around the condenser which cools the vapour and condenses it back into a liquid (distillate) . the distillate will be a pure substance