Chemistry end of year revision y9

Question 1

list some properties and uses of Glass Ceramics

Answer 1

Transparent and strong, glass insulates against heat

Glass ceramics are also more durable than other materials hence they are better suited for use in windows than plastic

Most of the glass produced is soda-lime glass which is made by heating a mixture of limestone, sand and sodium carbonate (soda) until it melts

On cooling it solidifies to form glass

A variation is borosilicate glass which is made using sand and boron trioxide and has a higher melting point than soda-lime glass

Question 2

list properties and uses of clay ceramics

Answer 2

Clay Ceramics

These are hardened materials that resist compressive forces

Clay is a soft material dug up from the earth which hardens at high temperatures and when it is fired, produces a very strong and hard material

This allows bricks to be used to build walls which withstand the weight and pressure of the material bearing downwards on itself

Question 3

list some properties nd uses of polymers

Answer 3

Polymers

Usually tough and flexible, some specialist polymers can be brittle

Poor conductor of heat and electricity

These properties are extremely useful for insulating electrical wiring as they prevent electric shocks and overheating

Question 4

lsit some properties and uses of composites

Answer 4

Composites

Made from two components: reinforcement and matrix

The matrix is what binds the reinforcement together

Common examples include fibreglass and steel reinforced concrete

The properties of composites depend on the reinforcement and matrix used so composites can be tailor engineered to meet specific needs

Question 5

list some properties and uses of metals

Answer 5

Metals

Shiny, malleable and ductile so can be hammered into different shapes

Can be mixed with other elements to form alloys, which have different properties to the elements they contain

Corrosion resistant metals can be produced which last longer than other metals

Good conductors of heat and electricity

Question 6

what is the difference between alloys and composites

Answer 6

Alloys are uniform mixtures of metals whereas composites have two or more distinguishable materials.

Question 7

give examples and uses of 2 types of composites

justify why

Answer 7

Reinforced concrete

Steel reinforced concrete has immense tensile and compressive strength allowing it to be used as columns and supporting structures in construction

Carbon-Fibre Composites

Carbon fibres composites are extremely strong and low weight, hence they are used in aviation, aeronautics and for making professional racing bicycles

Question 8

polymers can be moulded easily into an infinite variety of shapes

explain why

Answer 8

they have low melting point

Question 9

evaluate the advantages of recycling metals and how recycling can preserve both the environment and the supply of valuable raw materials.

Answer 9

• Recycling of metals enables us to preserve natural resources.
• Recycling emits less carbon dioxide and other harmful gases.

Aluminiu for example

£36,000,000 worth of aluminium is thrown away each year.

Aluminium cans can be recycled and ready to use in just 6 weeks.

1 recycled tin can would save enough energy to power a television for 3 hours.

Question 10

•Chose two properties of steel alloy that make it suitable for use as the ball in a hip joint.

A.Unreactive

B.good thermal conductor

C.good electrical conductor

D.Magnetic

E.High density

F.Strong

Answer 10

a

f

Question 11

describe the recycling of some materials

Answer 11

cans

paper

plastic bottles

Question 12

label the diagram

Answer 12

Question 13

Outer layer of the Earth. The thinnest layer of the four. Solid rock layer that we live upon.

Answer 13

crust

Question 14

Liquid layer of the core. Extremely hot. Made up of iron and nickel.

Answer 14

outer core

Question 15

Hottest part of the Erath. It is solid and made up of iron and nickel.

Answer 15

inner core

Question 16

Widest section of the Earth. Made up of semi-molten rock called Magma.

Answer 16

mantle

Question 17

What are tectonic plates?

Answer 17

Tectonic plates are pieces of the rocky outer layer of the Earth known as the crust. These plates are constantly moving, and volcanoes and earthquakes are found at plate boundaries.

Question 18

•Why do tectonic plates move?

Answer 18

plate movement is driven by a mechanism called slab pull. Slab pull occurs where older, denser tectonic plates sink into the mantle. As these older sections of plates sink, newer and less dense sections of plate are pulled along behind. Sinking in one place leads to plates spreading apart in other places.

Question 19

how do volcanos form?

Answer 19

Earthquakes and volcanoes are primarily found at plate boundaries. The plates are like giant rafts that slowly move around. At the boundaries between plates, molten magma is able to force its way to the surface and escape as lava.

Question 20

How could we determine if a substance is pure or impure?

Answer 20

melting and boiling points

Question 21

fill in the table

Answer 21

Question 22

list the 3 types of rocks and give examples

Answer 22

igneous (for example, basalt and granite)

sedimentary (for example, limestone, sandstone and shale)

metamorphic (for example, slate and marble)

Question 23

summarize the rock cycle

Answer 23

Question 24

move to test

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Question 25

Chromatography

Test your knowledge

https://www.bbc.co.uk/bitesize/topics/zych6g8/articles/zkqjjsg#zx844xs7

Question 26

Can you name two examples of compounds?

Answer 26

H2O

Co2

Question 27

Which of the following, if any, is a pure substance?

• Sea water
• Water in a mountain stream
• Distilled water in the school science laboratory
• None of the above

Answer 27

None of the above

Question 28

evaporation and condensation, Physical processes, or chemical processes?

explain why

Answer 28

Physical processes,

do not break chemical bonds.

Question 29

Impurities ———–the boiling point and —————-the melting point of water.

Answer 29

Impurities increase the boiling point and decrease the melting point of water.

Question 30

a separation technique used to separate a solvent from a mixture

Answer 30

Distillation

Question 31

If there are two different liquids with different boiling points, they can also be separated using —————.

Answer 31

If there are two different liquids with different boiling points, they can also be separated using fractional distillation.

Question 32

Examples of sedimentary rock are:

Answer 32

chalk

limestone

shale

sandstone

Question 33

what are the processes of making the sedimentary rock

Answer 33

transport → deposition → sedimentation → compaction → cementation

Question 34

———-igneous rocks form from magma that erupted onto the surface as lava, where it cooled quickly. On the other hand, ———-igneous rocks form from magma that cooled slowly, deep underground.

Answer 34

Extrusive igneous rocks form from magma that erupted onto the surface as lava, where it cooled quickly. On the other hand, intrusive igneous rocks form from magma that cooled slowly, deep underground.

Question 35

Metamorphic rocks rarely contain fossils.

explain why

Answer 35

Metamorphic rocks are formed from other rocks that are changed because of heat or pressure.

Question 36

move to test

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Question 37

difference between physical and chemical reactions

Answer 37

Physical changes, such as melting, boiling and dissolving, do not make new chemicals. They are usually easy to reverse.

In a chemical reaction, chemical bonds between atoms are broken and made, so the atoms get rearranged into new substances.

Question 38

what happens to atoms in chemical reactions?

Answer 38

Atoms are rearranged during a chemical reaction, but the number of atoms does not change.

Question 39

The simplest kind of chemical reactions involve two ——-reacting together to make a ———–.

Answer 39

The simplest kind of chemical reactions involve two elements reacting together to make a compound.

Question 40

what are the evidences of chemical reactions?

Answer 40

Evidence of chemical reactions includes a large temperature change, bubbles, or a colour change.

Question 42

Can you name some differences between a physical change and a chemical reaction?

Answer 42

Physical changes like melting and dissolving are usually easy to reverse, but chemical reactions are usually impossible to undo.

Chemical reactions often involve a large energy change, bubbles, or a colour change as new chemical reactions are made

Question 43

Summarise the following reaction with a symbol equation, including state symbols.

Liquid hexane (C₆H₁₄) reacts with oxygen gas (O₂). The products are carbon dioxide gas (CO₂) and liquid water (H₂O).

Answer 43

C₆H₁₄(l) + O₂(g) → CO₂(g) + H₂O(l)

Question 44

During chemical reactions or a change of state, atoms are created or destroyed

true /false

Answer 44

false

no atom are created or destroyed

Question 45

the mass of the frozen water is the same as the mass of the liquid water

explain why

Answer 45

No atoms were created or destroyed, so the mass of the water/ice stayed the same.

Question 46

Law of Conservation of Mass.

Answer 46

when a physical change or chemical reaction happens, the mass of the chemicals before is the same as the mass of the chemicals after.

Question 47

How much carbon is needed to produce 88 g of carbon dioxide, if 64 g is oxygen?

Answer 47

88 g - 64 g = 24 g

Question 48

go to quiz

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Question 49

examples of bases

Answer 49

metal oxides, such as copper oxide

metal hydroxides, such as sodium hydroxide, or

metal carbonates, such as calcium carbonate