Chemistry B

Question 1

What is an exothermic reaction?

Answer 1

Transfers energy to surroundings e.g. neutralization

Question 2

What is an endothermic reaction?

Answer 2

Takes energy from surroundings e.g. thermal decomposition.

Question 3

What reaction occurs when an acid and alkali react together?

Answer 3

Exothermic reaction

Question 4

What ions are always found in an acid?

Answer 4

Hydrogen (H+)

Question 5

What ions are always found in an alkali?

Answer 5

OH-

Question 6

What factors affect rate of reaction?

Answer 6

Temperature, concentration and surface area

Question 7

What is the collision theory?

Answer 7

Particles must collide with sufficient energy. Amount of energy particles must have for reaction is activation energy. Must increase number of successful collisions.

Question 8

What is a catalyst?

Answer 8

A substance that increases rate of reaction, without being involved or used up in the chemical reaction.

Question 9

How can a solid be separated from a solution?

Answer 9

Filtering

Question 10

What is it called when two solutions are mixed?

Answer 10

Precipitate

Question 11

What happens in terms of ions and molecules when when an acid reacts with any alkali?

Answer 11

Hydrogen ions (from acid) reacts with hydrroxide ions (from alkali) to produce water. H+ + OH- = H2O

Question 12

What could you do to a solid to make it conduct electricity?

Answer 12

Melt it

Question 13

During electrolysis why do positive ions go to negative electrodes?

Answer 13

Because positives attract

Question 14

What do the ions turn into when they reach the negative electrode?

Answer 14

Atoms

Question 15

What is electroplating?

Answer 15

Coating a cheap metal with a thin layer of expensive metal.

Question 16

Why might the electrolyte contain cryolite?

Answer 16

Because it lowers melting point therefore less energy is needed to melt it.

Question 17

What is meant by electrolysis?

Answer 17

Decomposition and produces chemical reactions using elements.

Question 18

What can Soluble salts be made from by using acids to react them with?

Answer 18

Metals, insoluble bases and alkalis

Question 19

How are insoluble salts made?

Answer 19

By mixing appropriate solutions of ions so that a precipitate is formed. Precipitation can be used to remove unwanted ions from solutions.

Question 20

What is an anode?

Answer 20

Positive electrode

Question 21

What is a cathode?

Answer 21

Negative electrode

Question 22

What is an electrolyte?

Answer 22

A substance that you carry electrolysis on.

Question 23

What are electrodes?

Answer 23

Conductors that electricity enters or leaves an object.

Question 24

What is the first stage of electrolysis?

Answer 24

Apply heat to beaker to melt electrolyte to break down ions in compound.

Question 25

What is the second stage of electrolysis?

Answer 25

There will be a + and - electrode. Ions are free to move as compound has been melted.

Question 26

What is the third stage of electrolysis?

Answer 26

+ ions attracted to - electrode and - ions attracted to + electrode.

Question 27

What is the fourth stage of electrolysis?

Answer 27

Ions must be turned into atoms so electrons flow through electrode to balance out ions so they become an atom. + ions lose electrons and - ions gain electrons.

Question 28

Whats the problem if the compound is dissolved instead of melted during electrolysis?

Answer 28

OH- and H+ ions will be there and be attracted to the electrodes too.