S4 - Chemistry Test (2)

Question 1

What are polymers?

Answer 1

Giant molecules formed when lots of small molecules join together

Question 2

How are alkene monomers made?

Answer 2

By cracking long-chain alkanes

Question 3

What are the properties of poly(ethene) and what is it used for?

Answer 3

• Cheap
• Strong
• Plastic bags and bottles

Question 4

What are the properties of poly(propane) and what is it used for?

Answer 4

• Strong
• High elasticity
• Crates and ropes

Question 5

What are the properties of poly(chloroethene) and what is it used for?

Answer 5

• Rigid
• Building materials: drain pipes & insulating wiring

Question 6

What properties to polymers generally have?

Answer 6

• Light
• Don’t break
• Don’t rot
• Don’t conduct electricity
• Thermoplastic - can be melted and made into other shapes
• Thermoset - will not melt after forming

Question 7

What are alloys?

Answer 7

Metals and some non-metals mixed together

Question 8

What are the properties of stainless steel and what elements is it made up of?

Answer 8

• Strong & resists corrosion
• Iron & Chromium

Question 9

What are the properties of Duralumin and what elements is it made up of?

Answer 9

• Strong & low density
• Aluminium, copper & magnesium

Question 10

What elements do plants need?

Answer 10

Nitrogen, Potassium & Phosphorus

Question 11

What are the 2 types of fertilisers?

Answer 11

Natural & synthetic

Question 12

What are examples of natural fertilisers?

Answer 12

Compost or manure

Question 13

What are synthetic fertilisers?

Answer 13

Ionic compounds that contain either N, P or K

Question 14

What property does a good fertiliser have and why?

Answer 14

• Soluble in water
• So it can be absorbed through the roots

Question 15

What is ammonia and is it soluble?

Answer 15

A colourless gas with a pungent smell.
Yes.

Question 16

What solution does ammonia give?

Answer 16

An alkaline solution

Question 17

What is the Haber process and when was it developed?

Answer 17

It converts nitrogen and hydrogen gas into ammonia.
Early 20th century.

Question 18

What is the Ostwald process?

Answer 18

The production of nitric acid by catalytic oxidation of ammonia

Question 19

What is the catalyst used in the Ostwald process?

Answer 19

Platinum

Question 20

Why do atoms become radioactive?

Answer 20

Because their nuclei are unstable

Question 21

What happens when an atoms nucleus becomes unstable?

Answer 21

It will begin to decompose to release energy and particles

Question 22

What are the three types of radiation?

Answer 22

Alpha, beta, gamma

Question 23

What are uses for radiation?

Answer 23

Radioisotopes have a range of uses in medicine and in industry

Question 24

What is Americium 241 used for?

Answer 24

Put in smoke detectors

Question 25

What is Iodine 131 used for?

Answer 25

To treat thyroid cancer

Question 26

What is the half-life of an atom?

Answer 26

The time taken for the number of radioactive atoms in a substance to drop by half

Question 27

What happens when metals react with air?

Answer 27

They become metal oxides

Question 28

What happens when metals react with water?

Answer 28

They undergo a displacement reaction

Question 29

What is the equation for displacement reactions?

Answer 29

Metal + Water -> Alkali + Hydrogen

Question 30

What happens when metals react with acid?

Answer 30

Hydrogen gas is displaced and a salt solution is formed

Question 31

What is the reactivity series?

Answer 31

Lithium Potassium Barium Calcium Sodium Magnesium Aluminium Carbon Zinc Iron Nickel Tin Lead Hydrogen Copper Mercury Siver Gold Platinum

Question 32

From what element to what element reacts with oxygen?

Answer 32

Lithium -> Silver

Question 33

From what element to what element reacts with dilute acid?

Answer 33

Lithium -> Lead

Question 34

From what element to what element reacts with water?

Answer 34

Lithium -> sodium

Question 35

What are oxidation reactions?

Answer 35

Reactions that always involve the loss of electrons

Question 36

What are reduction reactions?

Answer 36

Reactions that always involve the gain in electrons

Question 37

What is corrosion?

Answer 37

The breakdown of a metal by chemical reactions with its environment

Question 38

What must be present for corrosion to take place?

Answer 38

Oxygen and water

Question 39

What happens when metals corrode?

Answer 39

They become weak and dull

Question 40

What methods do we use to protect metals from corrosion?

Answer 40

- Physical barriers - Electrochemical protection - Galvanising

Question 41

What are examples of physical barriers when protecting metals from corrosion?

Answer 41

Paint, oil, plastic or a less reactive metal

Question 42

What does electrochemical protection involve when protecting metals from corrosion?

Answer 42

Giving the metal electrons to stop it corroding

Question 43

What does galvanising involve when protecting metals from corrosion and why?

Answer 43

Coating the metal with zinc. Zinc has a natural oxide layer which stops it corroding.

Question 44

What reaction is extracting metals an example of?

Answer 44

A reduction reaction

Question 45

What are the methods of extraction for the elements in the reactivity series?

Answer 45

Question 46

What do chemical cells do?

Answer 46

Convert chemical energy to electrical energy

Question 47

What is a battery?

Answer 47

2 or more chemical cells joined together

Question 48

What does a simple chemical cell consist of?

Answer 48

2 electrodes made of different metals and an electrolyte

Question 49

What is an electrolyte?

Answer 49

A solution/material that can conduct electricity

Question 50

Why are electrolytes important?

Answer 50

To complete a circuit

Question 51

What is an ion/salt bridge used for and what does it do?

Answer 51

Link 2 cells together, complete a circuit