chem filtration/allotropes paper 1

Question 1

how can a mixture be separated using filtration?

Answer 1

-line filter funnel w filter paper , the solvent and solute pass through it forming a filtrate . the insolube substances that dont pass are residue

Question 2

how can mixtures be separated using crystallization

Answer 2

solutes can be separated from a solution by evaporating the solvent leaving the solutes behind.

Question 3

chromatography can be used to …

Answer 3

find out what coloured compounds a mixture contains

Question 4

in paper chromatography what is the mobile stationary phase and chromatogram

Answer 4

mobile - the solvent
stationary phase - the paper contains the s.p
chromatogram - paper w the separated components on

Question 5

how do u work out retention value?

Answer 5

distance moved by spot / distance moved by solvent

Question 6

what is distillation?
fractional distillation?

Answer 6

separation of 2 liquids
separation of 2 or more liquids

Question 7

how does fd work?

Answer 7

1. liquid w lowest boiling point evaporates first and rises up fractionating column
2. condenses and cools and drips into flask
3. replace the flask

Question 8

describe the structure of an ionic compound

Answer 8

-lattice structure consisting of a regular arrangement of ions
-held together by strong electrostatic forces
between oppositely-charged ions

Question 9

state the properties of ionic compounds

Answer 9

high melting points and boiling points
-conducts electricity when the ions are molten or aqueous in solution

Question 10

typical size of an atom or molecule

Answer 10

10 to the power of -10

Question 11

Explain the properties of typical covalent bond

Answer 11

• low melting points and boiling points, due to weak forces of attraction between molecules (intermol). Doesnt take much energy to overcome these
• strong cov bonds
• poor conduction of electricity

Question 12

what are two examples of giant covalent structures

Answer 12

graphite and diamond

Question 13

describe the structure of graphite.

Answer 13

-3 cov bonds for each carbon atom
-high melting points
-layered strucuture means , deloc electrons = conduct elec

Question 14

describe the structure of diamond

Answer 14

-4 cov bonds for each carbon atom
-hard, high mp, rigid network of carbon atoms
.strong covalent bonds
-electrical insulator as there’s no free charged particles

Question 15

Explain, in terms of structure and bonding, why graphite is used
to make electrodes and as a lubricant, whereas diamond is used
in cutting tools

Answer 15

sheets of carbon atoms in graphite r held tog by weak forces of attraction allow layers to slide over each other = soft

hard, rigid structure , strong cov bonds, tetrahedral arrangement

Question 16

structure of fullerene

Answer 16

spherical, weak intm forces bet molec, low mp, soft slippery, molec themselves are v strong due to their covalent bonding

Question 17

structure of graphene

Answer 17

sheet of carbon atoms, one atom thick, strong cov bonds, conductor

Question 18

most non-metals have…

Answer 18

low boiling points and are poor
conductors of electricity