U3-1 - Metals

Question 1

Metal + Oxygen → …

Answer 1

Metal oxide

Question 2

Metal + Water → …

Answer 2

Metal hydroxide + Hydrogen

Question 3

Metal + Acid → …

Answer 3

Salt + Hydrogen

Question 4

Chemical test for hydrogen gas

Answer 4

Burns with a (squeaky) pop

Question 5

Very reactive metals must be extracted from their ores via …

Answer 5

electrolysis.

Question 6

Metals around the middle of the ECS can be extracted from their ores via …

Answer 6

heating with carbon.

Question 7

Very unreactive metals can be extracted from their ores via …

Answer 7

heating alone.

Question 8

What type of metal pairs generate higher voltages in electrochemical cells?

Answer 8

Far apart in the ECS

Question 9

What is the direction of electron flow in electrochemical cells?

Answer 9

From metal higher in the ECS to metal lower in the ECS

(remember - electrons flow down)

Question 10

Describe the structure of a metal lattice

Answer 10

Positive metal ions surrounded by delocalised electrons

Question 11

Metallic bond

Answer 11

Electrostatic attraction between positive metal ions and delocalised electrons

Question 12

Displacement reaction

Answer 12

A reaction in which a more reactive metal displaces a less reactive metal from a compound.

E.g. Mg + FeSO₄ → MgSO₄ + Fe

Question 13

What allows metals to conduct electricity?

Answer 13

Delocalised electrons

(charged particles + free to move)

Question 14

Why must a d.c. supply be used during electrolysis?

Answer 14

So that the products can be identified.

Question 15

Redox reaction

Answer 15

A reaction involving a transfer of electrons.

(One reactant loses electrons, the other gains them)

Question 16

Loss of electrons

Answer 16

Oxidation

(remember - OIL RIG)

Question 17

Gain of electrons

Answer 17

Reduction

(remember - OIL RIG)

Question 18

Oxidation

Answer 18

Loss of electrons

(rememeber - OIL RIG)

Question 19

Reduction

Answer 19

Gain of electrons

(rememeber - OIL RIG)

Question 20

How do you turn this reduction equation into an oxidation equation?

Cu²⁺ + 2e^– → Cu

Answer 20

Reverse it

Cu → Cu²⁺ + 2e^–

Question 21

When copying equations from the ECS, which equation gets reversed?

Answer 21

The one higher up in the ECS

Question 22

What has to be done before these equations can be added up?

Answer 22

Electrons must be balanced

(so multiply whole Na equation by 2)

Question 23

What type of reaction is this?

MgO + H₂SO₄ → MgSO₄ + H₂O

Answer 23

Neutralisation

(base + acid)

Question 24

What type of reaction is this?

C₂H₄ + Br₂ → C₂H₄Br₂

Answer 24

Addition

(multiple reactants, only one product)

Question 25

What type of reaction is this?

3Na(s) + AlCl₃(aq) → 3NaCl(aq) + Al(s)

Answer 25

Displacement

(Na displaces Al from a compound)

Question 26

What type of reaction is this?

Li(s) + HCl(aq) → LiCl(aq) + H₂(g)

Answer 26

Redox

(Li loses electrons, H⁺ gains electrons)

Question 27

What type of reaction is this?

AgNO₃(aq) + KCl(aq) → AgCl(s) + KNO₃(aq)

Answer 27

Precipitation

(solid is formed, AgCl)

Question 28

What is wrong with this redox equation?

Cu²⁺ + Ag + e^– → Cu + Ag⁺

Answer 28

Still has e^–

(Electrons were not balanced before adding up equations)

Question 29

What is an advantage of graphite electrodes (over metal ones)?

Answer 29

They do not corrode over time

Question 30

Name X

Answer 30

Ion bridge

(or salt bridge)

Question 31

What is the purpose of the ion bridge?

Answer 31

Completes the circuit

(or allows ions to flow)