Chemical Changes - Acids, Bases and REDOX reactions

Question 1

What is the pH scale used for?

Answer 1

To measure how acidic or Alkaline a solution is

From 0-14 (0 being most acidic)

Question 2

How can you measure the pH of a Solution?

Answer 2

Using an indicator that changes colour depending on the certain pH of the solution.

Question 3

What Ions form with acids in water?

Answer 3

H+ Ions

Question 4

What is a base?

Answer 4

Any substance that will react with an acid to form a salt.

Question 5

What Ions do Alkalis form in water

Answer 5

OH- Ions

Question 6

What is Neutralization?

Answer 6

A reaction between acids and bases, the products will be neutral pH 7

Question 7

What do acids do in aqueous solutions?

Answer 7

They ionise them

Question 8

What do strong acids do in water?

Answer 8

They fully ionise, all acid particles dissociate to release H+ ions.

Question 9

What do weak acids do in water?

Answer 9

They do not fully ionise, low amount of H+ ions formed

Question 10

What type of reaction is the ionisation of weak acids?

Answer 10

Reversible Reaction

Question 11

What does 1 decrease of 1 on the pH scale equate to?

Answer 11

The concentration of H+ ions increases by a factor of 10

Question 12

How is the strength of an acid different from the concentration of acid?

Answer 12

Strength - the proportion of acid molecules ionise in water

Concentration - the amount of acid in a certain volume of water

Question 13

What is formed when Acid reacts with a Metal Oxide?

Answer 13

Acid + Metal Oxide —> SALT + WATER

Question 14

What is formed when Acid reacts with a Metal Hydroxide?

Answer 14

Acid + Metal Hydroxide ——-> SALT + WATER

Question 15

What is formed when Acid reacts with a Metal Carbonate?

Answer 15

Acid + Metal Carbonate —-> SALT + WATER + CARBON DIOXIDE

Question 16

What is the Reactivity Series?

Answer 16

It is a list that orders metals from most to least reactive

Question 17

How is reactivity determined for metals?

Answer 17

How easily they lose electrons - forming positive ions

higher up the metal, the easier to lose an electron

Question 18

Why is Carbon included in the reactivity series?

Answer 18

Metals less reactive than carbon can be extracted from the ores by reduction (with carbon). Those above cannot

Question 19

Why is Hydrogen included in the reactivity series?

Answer 19

Metals more reactive than hydrogen will react with acids.

Metals less reactive will not.

Question 20

What is formed when Acid reacts with a Metal?

Answer 20

Metal + Acid —-> SALT + HYDROGEN

Question 21

What shows the speed of the reaction between acid and metals?

Answer 21

The rate at which hydrogen bubbles are given off.

Question 22

What is formed when Metals react with Water?

Answer 22

Metal + Water —-> METAL HYDROXIDE + HYDROGEN

Question 23

What is Oxidation? (in terms of electrons)

Answer 23

The loss of electrons

Question 24

What is a Reduction? (in terms of electrons)

Answer 24

The gaining of electrons

Question 25

How do metal ores less reactive than carbon extract?

Answer 25

The ore is reacted with carbon, which then becomes oxidised, which reduces the metal ore. Leaving, the Metal and Carbon Dioxide

Question 26

What does OIL RIG mean?

Answer 26

Oxidation Is Loss, Reduction Is Gain

Question 27

What is a REDOX reaction?

Answer 27

When Oxidation and Reduction happen at the same time.

Question 28

What is an example of a REDOX reaction?

Answer 28

All reactions between Metals with Acids

Question 29

What is the Metal displacement rule?

Answer 29

A MORE reactive metal will displace a LESS reactive metal from its compound.

Question 30

What happens to Metal Ions in a displacement reaction?

Answer 30

They gain electrons as they are reduced

Question 31

What happens to Metal Atom in a displacement reaction?

Answer 31

They lose electrons as they are oxidised