separating and purifying substances

Question 1

why do we sometimes need to use fractional distillation?

Answer 1

to separate substances that are similar in boiling points

Question 2

what is the difference between fractional distillation and simple distillation?

Answer 2

simple distillation is for substances that have different in boiling points and fractional distillation is for substances that have similar boiling points

Question 3

what does fractional distillation include in its equipment that simple distillation doesn’t have?

Answer 3

a fractionating coloumn

Question 4

how does simple distillation work?

Answer 4

the substance with the lowest boiling point is evaporated and rises to the top, goes through the condenser and condenses and turns into a liquid then gets collected into the beaker

Question 5

how does fractional distillation work?

Answer 5

the substance with the lowest boiling point is evaporated however due to the fact that the substances are similar in boiling points, the substance is evaporated and goes up the fractionating column and the substance that is evaporated before it’s supposed to will fall back down into the flask. the substance that has been successfully evaporated will go through the condenser, condense, turn to a liquid, and be collected into the beaker

Question 6

what is a pure substance?

Answer 6

a substance that has only one one element or compound that makes it up

Question 7

what is a brief explanation of the process of crystallisation?

Answer 7

the substance is heated until it begins to evaporate leaving the solid behind as crystals

Question 8

what is potable water?

Answer 8

drinkable water

Question 9

what is a mixture?

Answer 9

substances that are mixed together but not chemically bonded

Question 10

what is filtration?

Answer 10

when an insoluble solid is filtered from a liquid through filter paper

Question 11

what does chromatography do?

Answer 11

identifies and separates substances

Question 12

what is the formula for rf value?

Answer 12

substance/solvent

Question 13

what are the 3 ways to get potable water?

Answer 13

filtration, sedimentation and chlorination

Question 14

what is the process of sedimentation?

Answer 14

leave water and let big bits such as mud,rocks,etc to float to the bottom

Question 15

what is the process of filtration?

Answer 15

filter water to remove finer bits - any really small particles of mud or other debris

Question 16

what is the process of chlorination?

Answer 16

using chlorine to remove any pathogens or microorganisms to make it clean and safe for drinking

Question 17

what are the two lines that are drawn on the chromatography paper called?

Answer 17

origin line and solvent front