Chemical Changes and Structures

Question 1

What is the pH scale a measure of?

Answer 1

The concentration of hydrogen ions in a substance

Question 2

What is a neutral solution?

Answer 2

A solution with the same concentration of hydrogen and hydroxide ions

Question 3

What is the pH of a neutral solution?

Answer 3

7

Question 4

What is the pH of an acidic solution?

Answer 4

Less than 7

Question 5

What is the pH of an alkaline solution?

Answer 5

More than 7

Question 6

Does an alkaline solution have a higher concentration of hydrogen or hydroxide ions?

Answer 6

hydroxide ions

Question 7

How will the dilution of an acidic solution affect the pH?

Answer 7

It will increase the pH, bringing it closer to 7

Question 8

How will the dilution of an alkaline solution affect the pH?

Answer 8

It will decrease the pH, bringing it closer to 7

Question 9

What is dissolved in water to form an acidic solution?

Answer 9

non-metal oxides

Question 10

What is the word equation for the formation of an acid?

Answer 10

non-metal oxide + water –> acid

Question 11

What is the word equation for the formation of a metal hydroxide?

Answer 11

metal oxide + water –> metal hydroxide

Question 12

What is a neutralisation reaction?

Answer 12

A reaction in which a metal oxide reacts with an acid to make water and a salt

Question 13

What is the word equation for a neutralisation reaction?

Answer 13

metal oxide + acid –> water + salt

Question 14

What is produced when a metal carbonate reacts with and acid

Answer 14

a salt, water and carbon dioxide

Question 15

What is the word equation for the reaction between a metal carbonate and an acid?

Answer 15

metal carbonate + acid –> salt + water + carbon dioxide

Question 16

what is the word equation for the reaction between a metal and an acid?

Answer 16

metal + acid –> salt + hydrogen

Question 17

How is a salt named?

Answer 17

the first part is named from the the metal in the base that was used
the second part comes from the acid used

Question 18

What are the factors affecting rate of reaction?

Answer 18

• temperature
• concentration
• particle size/surface area
• use of a catalyst

Question 19

What is a catalyst?

Answer 19

a substance that speeds up a chemical reaction and remain unchanged by the reaction

Question 20

How are elements in the periodic table arranged?

Answer 20

In order of increasing atomic number

Question 21

What are covalent bonds?

Answer 21

a bond formed between two non-metal atoms formed when two positive nuclei are held together by their attraction for a shared pair of electrons

Question 22

What are the diatomic elements?

Answer 22

Hydrogen, Nitrogen, Florine, Oxygen, Iodine, Chlorine and Bromine

Question 23

What are the properties of a covalent molecular substance?

Answer 23

• they have strong covalent bonds with molecules and weak attraction between the molecules
• have low melting and boiling points
• do not conduct electricity because their electrons are not free to move

Question 24

What are the properties of covalent network structures?

Answer 24

• have a network of strong covalent bonds within one giant structure
• have very high melting and boiling points
• do not dissolve

Question 25

How are ions formed?

Answer 25

when atoms lose or gain electrons to become stable

Question 26

What are ionic bonds?

Answer 26

the electrostatic attraction between positive and negative ions

Question 27

Why do ionic compounds have high melting and boiling points?

Answer 27

Because strong ionic bonds must be broken

Question 28

When do ionic compounds conduct electricity?

Answer 28

when molten or in solution

Question 29

What is the valency of the noble gases?

Answer 29

0