Chemistry

Question 1

What is the charge of Silver (Ag)

Answer 1

Ag+

Question 2

What is the charge of Copper (Cu)

Answer 2

Cu2+

Question 3

What is the charge of Iron (Fe)

Answer 3

Fe2+ / Fe3+

Question 4

What is the charge of Iron (Pb)

Answer 4

Pb2+

Question 5

What is the charge of Zinc (Zn)

Answer 5

Zn2+

Question 6

What is the charge of Ammonium (NH₄)

Answer 6

NH₄+

Question 7

What is the charge of Hydroxide (OH)

Answer 7

OH-

Question 8

What is the charge of Carbonate (CO₃)

Answer 8

CO₃ 2-

Question 9

What is the charge of Nitrate (NO₃)

Answer 9

NO₃-

Question 10

What is the charge of Sulfate (SO₄)

Answer 10

SO₄ 2-

Question 11

What happens when lithium reacts with water and what does it produce?

Answer 11

It floats and fizzes whilst the solid disappears. It produces Lithium Hydroxide + Hydrogen

Question 12

What happens when the group 1 alkali metals react with air?

Answer 12

They all react with oxygen to produce an oxide

Question 13

What happens when sodium reacts with water and what does it produce?

Answer 13

It melts into a ball and fizzes quickly, producing sodium hydroxide and hydrogen

Question 14

What happens when potassium reacts with water and what does it produce?

Answer 14

It sparks and reacts vigorously, producing potassium hydroxide and hydrogen

Question 15

Describe chlorine.

Answer 15

• Pale yellow-green gas at room temperature
• Very reactive and poisonous gas
• Pale green in aqueous solution

Question 16

Describe bromine.

Answer 16

• Red-brown liquid at room temperature
• Reactive, poisonous and dense gas
• Orange in aqueous solution

Question 17

Describe iodine.

Answer 17

• Grey solid at room temperature
• Shimmery, crystalline solid that sublimes to form a purple vapour
• Dark brown in aqueous solution

Question 18

What happens when magnesium reacts with oxygen?

Answer 18

Bright white flame and white powder (magnesium oxide) is produced

Question 19

What happens when hydrogen reacts with oxygen?

Answer 19

Exothermic reaction and water is produced

Question 20

What happens when sulfur reacts with oxygen?

Answer 20

Blue flame and colourless, poisonous gas is produced

Question 21

Describe the colour change of the thermal decomposition of copper carbonate.

Answer 21

Copper carbonate (green) -> copper oxide (black)

Question 22

What is the order of reactivity abbreviation?

Answer 22

Please Send Lions Cats Monkeys And Zebras Into Countries Signed Gordon

Question 23

Define oxidation.

Answer 23

Gain of oxygen OR loss of electrons

Question 24

Define reduction.

Answer 24

Loss of oxygen OR gain of electrons

Question 25

Define redox.

Answer 25

A reaction in which both oxidation and reduction occur

Question 26

Define an oxidising agent.

Answer 26

Causes another reactant to be oxidised and is reduced itself

Question 27

Define a reducing agent.

Answer 27

Causes another reactant to be reduced and is oxidised itself

Question 28

Describe the colours of methyl orange in different pH solutions.

Answer 28

Acidic - Red-orange Neutral - Yellow Alkali - Yellow

Question 29

Which salts are always soluble?

Answer 29

- Sodium - Potassium - Ammonium - Nitrates

Question 30

When are chlorides insoluble?

Answer 30

With silver and lead

Question 31

When are sulfates insoluble?

Answer 31

With barium, calcium and lead

Question 32

When are carbonates soluble?

Answer 32

With sodium, potassium and ammonium

Question 33

When are hydroxides soluble?

Answer 33

With sodium, potassium, ammonium and calcium

Question 34

When metals, bases and carbonates react with acids what do they produce?

Answer 34

- Metal + Acid -> Salt + Hydrogen - Base + Acid -> Salt + Water - Carbonate + Acid -> Salt + Water + Carbon Dioxide

Question 35

What is the chemical test for ammonia and chlorine gases?

Answer 35

- Ammonia: Damp red litmus -> Blue - Chlorine: Damp blue litmus -> White

Question 36

What are the colours from the different flame tests?

Answer 36

- Lithium = Red - Sodium = Yellow - Potassium = Lilac - Calcium = Orange-red - Copper = Blue-green

Question 37

Describe the test for ammonium.

Answer 37

- Add sodium hydroxide - Heat the solution - Test gas for ammonia (damp red litmus)

Question 38

Describe the tests for Cu2+, Fe2+ and Fe3+.

Answer 38

- Dissolve sample in water - Add drops of sodium hydroxide - Observe the precipitate colour - Fe2+ = Green - Fe3+ = Brown - Cu2+ = Blue

Question 39

Describe the test for Cl-, Br- and I- (halides).

Answer 39

- Dissolve sample in water - Add acidified silver nitrate - Cl- = White ppt - Br- = Cream ppt - I- = Yellow ppt

Question 40

Describe the test for sulfate ions.

Answer 40

- Add acidified barium chloride - White precipitate will form if present

Question 41

Describe the test for carbonate ions.

Answer 41

- Add hydrochloric acid - Bubble gas into limewater - Will go cloudy if present

Question 42

How do catalysts speed up the rate of reaction?

Answer 42

- Provide an alternative pathway with a lower activation energy - Which increases the proportion of particles with energy to react

Question 43

Describe the reaction of the dehydration of hydrated copper(II) sulfate

Answer 43

- Anhydrous copper(II) sulfate + water ⇌ hydrated copper(II) sulfate - White solid turns blue in presence of water - Forward reaction add water - Reverse reaction heat the hydrated copper(II) sulfate (water evaporates)

Question 44

Describe the reaction of the effect of heat on ammonium chloride

Answer 44

- Ammonium chloride ⇌ ammonia + hydrogen chloride - The white solid (ammonium chloride) breaks down into ammonia and hydrogen chloride (colourless gases) using heat - These gases can then react to form ammonium chloride

Question 45

What are some characteristics of the compounds in a homologous series?

Answer 45

- Same general formula - Same functional group - Similar chemical properties - Trend in physical properties

Question 46

What does complete combustion produce?

Answer 46

Carbon Dioxide + Water

Question 47

What does incomplete combustion produce?

Answer 47

Carbon Dioxide, Carbon Monoxide and Water

Question 48

Why is cracking useful in the oil industry?

Answer 48

It produces shorter molecules called alkenes which are more useful as they burn more cleanly. Alkenes are also used to make alcohol

Question 49

What are the reagents of catalytic cracking.

Answer 49

- 650C - Silica catalyst

Question 50

What are the reactions called with halogens and alkanes/alkenes?

Answer 50

- Alkanes = Substitution - Alkenes = Addition

Question 51

What is the colour change of alkanes and alkenes with bromine water?

Answer 51

- Alkanes = Orange -> Orange, Bromine unreacted - Alkenes = Orange -> Colourless, Bromine reacted

Question 52

What is polymerisation?

Answer 52

The process of many monomers joining together to form a polymer

Question 53

What are the problems of disposing addition polymers?

Answer 53

- They can't biodegrade - They produce toxic gases when burned