EOY

Question 1

Advantages of nanoparticles in suncream?

Answer 1

better coverage

more protection from the sun’s UV rays

Question 2

Disadvantages of nanoparticles in suncream?

Answer 2

may cause potential cell damage to the body

could have harmful effects on the environment

Question 3

Order of sizes

Answer 3

dm, cm , mm , um (micrometre), nm

Question 4

Pure substance

Answer 4

a single element or single compound

Question 5

What is the test for chlorine gas?

Answer 5

a damp litmus paper turns white

Question 6

oxides of nitrogen cause

Answer 6

acid rain

Question 7

particulate matter causes

Answer 7

global dimming

Question 8

what is the relative mass of an electron?

Answer 8

very small

Question 9

what is the relative mass of a proton and neutron?

Answer 9

1

Question 10

Why are instrumental methods used to measure gas?

Answer 10

accurate

Question 11

Compounds formed from only non-metals consist of particles called?

Answer 11

molecules

Question 12

Compounds formed when non-metals react with metals consist of particles called?

Answer 12

ions

Question 13

The relative formula mass of a substance, in grams, is one … of the substance

Answer 13

mole

Question 14

Why did Mendeleev leave gaps?

Answer 14

for undiscovered elements

Question 15

State two similarities between hydrogen and atoms in group 1?

Answer 15

they have 1 electron in their outer shell

forms ions with a 1+ charge

Question 16

Describe how knowledge of the numbers of protons and electrons in atoms allow chemists to place elements in their correct order and correct group.

Answer 16

number of electrons = number of protons
chemical properties depend on the outer electrons
number of shells gives the period

Question 17

There are no transition elements between the Group 2 element magnesium and the Group 3 element aluminium.
Give a reason why, in terms of electronic structure.

Answer 17

2nd shell can only have a maximum of 8 electrons

Question 18

Suggest what predictions Mendeleev was able to make about these undiscovered elements.

Answer 18

predicted their properties

predicted that they were metals

Question 19

Why is lithium less reactive than potassium, in terms of electronic structure?

Answer 19

outer shells are closer to the nucleus

stronger force of attraction between the outermost electron and the nucleus, less easily lost in reaction

Question 20

State why transition metal oxides are added to pottery glazes

Answer 20

For colour

Question 21

State two properties which coinage metals should have

Answer 21

hard - so they don’t get scratched

unreactive - so they don’t corrode

Question 22

Explain 2 differences in the reactions of potassium and lithium with water

Answer 22

potassium
produces a lilac flame
melts and forms a ball

Question 23

Give 3 properties of why alkali metals should be grouped together

Answer 23

they form ions with 1+ charge
they are very reactive
they react with water to form alkaline solutions

Question 24

How did Mendeleev improve John Newland’s periodic table and why?

Answer 24

he left gaps for undiscovered elements

so that the elements would fit into their proper groups

Question 25

alcohol + .... ---> carbon dioxide + water

Answer 25

oxygen

Question 26

What is the functional group in an alcohol molecule?

Answer 26

OH-

Question 27

How do alkene molecules form a molecule of plastic?

Answer 27

double bond breaks | and the alkenes join together

Question 28

Not all molecules are compounds but ...

Answer 28

all compounds are molecules

Question 29

Suggest 2 of the main costs of making a plastic from crude oil

Answer 29

energy is required | cost of crude oil

Question 30

Suggest two problems caused by the disposal of plastics in landfill sites

Answer 30

landfill sites are filling up | not biodegradable

Question 31

Plastics made from plants would be more environmentally friendly than plastics made from crude oil, why?

Answer 31

Biodegradable | renewable resources

Question 32

Suggest a problem caused by plastics going to landfill sites.

Answer 32

there is not enough space in landfill sites

Question 33

How are resources saved by recycling more plastics

Answer 33

less crude oil is used

Question 34

Suggest why recycling, products made from C2H4 and C3H6 is difficult

Answer 34

two different polymers

Question 35

Why might repeats be conducted?

Answer 35

to improve accuracy to calculate an average to identify anomalous results

Question 36

Suggest why the student warmed the liquid hydrocarbon using warm water and not a Bunsen flame.

Answer 36

it is flammable

Question 37

Crude oil is a .... of different substances

Answer 37

mixture

Question 38

Why should sulfur be removed from petrol?

Answer 38

sulfur produces sulfur dioxide | which cause acid rain

Question 39

What is metallic bonding?

Answer 39

is the electrostatic attraction between metal ions and a sea of 'delocalised' electrons

Question 40

Suggest how the use of a suspension of limestone decreases one of the environmental impacts that the waste gases would cause

Answer 40

Sulfur dioxide and oxides of nitrogen both cause acid rain. They can be neutralised by calcium carbonate.

Question 41

Difference between a smart polymer and a regular polymer

Answer 41

a smart polymer can return to its original shape when conditions change

Question 42

Why is incomplete combustion of methane dangerous?

Answer 42

carbon monoxide is made | which combines with the haemoglobin and prevents oxygen from being carried in the blood

Question 43

Explain why, in terms of the energy involved in bond breaking and bond making, the combustion of methane is exothermic.

Answer 43

energy is required to break bonds energy is released when bonds are made more energy is released than energy taken in

Question 44

Why can graphine rub off?

Answer 44

layers have weak intermolecular forces | so they can slide over each other

Question 45

A nanodiamond contains a few ... atoms

Answer 45

hundred

Question 46

What is made from chlorine?

Answer 46

bleach

Question 47

carbon particles cause

Answer 47

global dimming

Question 48

How is carbon dioxide removed from the atmosphere?

Answer 48

plants / trees absorb carbon dioxide | coal 'locks up' carbon dioxide

Question 49

How to measure volume of gas produced?

Answer 49

The reaction mixture is connected to a gas syringe where gas is collected

Question 50

rate of reaction =

Answer 50

volume of gas produced / time taken

Question 51

Rate if resction is measured in

Answer 51

cm3/s

Question 52

How to measure change in mass?

Answer 52

Reaction is placed on a mass balance | As reaction proceeds, mass of the flask decreases as gas is given off

Question 53

Rate of reaction for gas is

Answer 53

g/s

Question 54

Explain how metals can conduct electricity (4 marks)

Answer 54

Metals are giant lattices that are made up of positive ions with delocalised electrons so electrons can move through the metal

Question 55

Describe how the structure of an alloy is different from the structure of a pure metal.

Answer 55

An alloy has different sizes of atoms | Alloys have distorted layers

Question 56

Why is nitinol used in dental braces?

Answer 56

can return to its original shape

Question 57

Explain why chlorine (Cl2) is a gas at room temperature, but sodium chloride (NaCl) is a solid at room temperature.

Answer 57

``` Chlorine - covalent bonds between atoms - forming simple molecules - so there is weak attraction between molecules - therefore has a low boiling point Sodium Chloride - ionic bonds - therefore strong bonds in all directions - between oppositely charged atoms - forming a giant lattice - so high boiling point ```