experimental chem

Question 1

length

Answer 1

metre (m), metre ruler or measuring tape

Question 2

temperature

Answer 2

kelvin (k), thermometer

Question 3

time

Answer 3

seconds (s), analogue/digital stopwatch

Question 4

mass

Answer 4

kilograms (kg), electronic/beam balance

Question 5

volume

Answer 5

cubic metre (m3), pipette/measuring cylinder/volumetric flask/burette

Question 6

pipette

Answer 6

measure fixed accurate volumes

Question 7

volumetric flask

Answer 7

measure fixed accurate volumes that are large

Question 8

measuring cylinder

Answer 8

measure volumes of a range to the nearest 0.5cm cube

Question 9

burette

Answer 9

measure volumes of a range to the nearest 0.05cm cube

Question 10

methods of gas collection

Answer 10

water displacement, gas syringe, downward delivery and upward delivery

Question 11

upward delivery

Answer 11

insoluble to soluble, less dense than air

Question 12

downward delivery

Answer 12

insoluble to soluble, denser than air

Question 13

water displacement

Answer 13

insoluble to slightly soluble, density doesnt affect gas collection

Question 14

gas collected during downward delivery

Answer 14

sulfur dioxide, chlorine and hydrogen chloride

Question 15

gas collected during upward delivery

Answer 15

ammonia

Question 16

gas collected during water displacement

Answer 16

hydrogen, carbon dioxide and oxygen

Question 17

magnetic attraction

Answer 17

separation of magnetic solids from non-magnetic solids by using a magnet

1. use a magnet to separate iron filings from sand or sulfur powder
2. magnet can be used to separate iron or steel from non-magnetic waste products such as plastic and cardboard

Question 18

sieving

Answer 18

a sieve can be used to separate solids with different particle sizes

Question 19

using suitable solvents

Answer 19

a suitable solvent can be used to separate solid-solid mixtures which only one of the solids is soluble in the solvent

Question 20

filtration

Answer 20

filtration can be used to separate insoluble solids from liquids

Question 21

evaporation to dryness

Answer 21

use to separate dissolved solids from its solvent by mixture until all solvent vaporises

Question 22

crystallisation

Answer 22

to obtain a pure solid from its saturated solution

Question 23

steps for crystallisation

Answer 23

1) heat solution until saturated
2) cool saturated solutions to form crystals
3) filter the mixture to obtain crystals
4) rinse crystals with cold distilled water to remove impurities
5) dry crystals between filter papers

Question 24

simple distillation

Answer 24

used to separate its pure solvent from its solution

Question 25

chromatography

Answer 25

used to separate a mixture of substances with different solubilities in a given solvent

Question 26

fractional distillation

Answer 26

used to separate miscible liquids with different boiling points