Chemical Changes

Question 1

What range of values can ph take

Answer 1

0-14

Question 2

What term is used to describe a solution when a pH of 7

Answer 2

Neutral

Question 3

What’s the difference between a strong and weak acid

Answer 3

Strong acids ionise water completely so all acid particles dissociate to release H+ ions weak acids do not ionise completely or dissociate to release H+ ions

Question 4

If the pH of the solution rises from 2 to 5 what factor has the hydrogen ion concentration of the solution changed by

Answer 4

Changes by 10 to the power of -3

Question 5

Name two substances formed when nitric acid reacts with copper hydroxide

Answer 5

Copper nitrate and water

Question 6

What is produced when an acid and a base react

Answer 6

Salt and water

Question 7

What is the reaction between an acid and a base called

Answer 7

Neutralisation

Question 8

What is produced when an acid reacts with a metal oxide

Answer 8

Salt and water

Question 9

What is produced when an acid reacts with a metal hydroxide

Answer 9

Salt and water

Question 10

What’s the difference between concentrated acids and strong acids

Answer 10

Concentration measures how much there is in a volume

Strong is what proportion the acid molecules ionise in water

Question 11

What is produced when an acid and metal carbonate react

Answer 11

Salt water and carbon dioxide

Question 12

Name the elements in the reactivity series

Answer 12

Potassium 
Sodium 
Lithium 
Calcium 
Magnesium 
Carbon
Zinc
Iron
Hydrogen 
Copper

Question 13

What is produced when an acid and a metal react

Answer 13

Salt and hydrogen

Question 14

What is produced when metal and water react

Answer 14

Metal hydroxide and hydrogen

Question 15

What is the chemical formula for hydroxide

Answer 15

OH

Question 16

In the reactivity series what elements can be extracted using electrolysis

Answer 16

Anything above carbon

Question 17

How are elements below carbon extracted and how

Answer 17

Reduction with carbon because the carbon takes away the oxygen from the metal which are less reactive than the metals themselves

Question 18

A loss of electrons is

Answer 18

Oxidation

Question 19

A gain of electrons is

Answer 19

Reduction

Question 20

What are all reactions with metal and acids called

Answer 20

Redox reactions

Question 21

What is a displacement reaction

Answer 21

When a more reactive halogen displaces a less reactive halogen from a salt solution

Question 22

A more reactive _____ will displace a less ______ ___ from its compound

Answer 22

A more reactive metal will displace a less reactive metal from its compound

Question 23

What determines the reactivity of a metal

Answer 23

How easily it loses electrons to form positive ions

Question 24

Magnesium is reacted with dilute hydrochloride acid. Give the name of the salt that is produced

Answer 24

Magnesium chloride

Question 25

Which two substances are made when a metal reacts with water

Answer 25

A metal hydroxide and hydrogen

Question 26

What are positive ions called

Answer 26

Cations

Question 27

What electrode do cations move towards and what is the charge of that electrode

Answer 27

The Cathode which is negative

Question 28

What are negative ions called

Answer 28

Anions

Question 29

What electrode do negative ions move to and what is the charge of that electrode

Answer 29

The anode which is positive

Question 30

What is an electrolyte

Answer 30

A dissolved or ionic compound that created a flow of charge as the ions are free to move

Question 31

What happens when ions move towards electrodes

Answer 31

They react and the compound decomposes and they lose of gain electrons

Question 32

Explain how bauxite is extracted

Answer 32

1) Aluminium most be extracted from its ore (bauxite) aluminium oxide by electrolysis 2) Aluminium oxide has a very high melting temperature so it’s mixed with cryolite to lower melting point 3) The molten mixture contains free ions an so it’ll conduct electricity 4) the positive aluminium ions move to the negative electrode where three electrons are gained they then sink to the bottom of the electrolysis tank 5) the negative oxygen ions move to the positive electrode each lose two electrons and combine with other oxygen atoms to from 02 molecule