Gas chemistry test

Question 1

What 3 ways can oxidation be defined as?

Answer 1

• Gain of oxygen
• Loss of hydrogen
• Loss of electrons

Question 2

What 3 ways can reduction be defined?

Answer 2

• Loss of oxygen
• Gain of hydrogen
• Gain of electrons

Question 3

What type of reaction is the extraction of aluminium?

Answer 3

• A redox reaction

Question 4

What is a positive electrode called?

Answer 4

Anode

Question 5

What is a negative electrode called?

Answer 5

Cathode

Question 6

What is the gas test for carbon dioxide?

Answer 6

CO2 is bubbled through limewater which turns the colourless solution milky. (White precipitate formed)

Question 7

CO2 + Ca(OH)2 =

Answer 7

CaCO3+H2O

Question 8

What happens to the white precipitate after it is formed?

Answer 8

It then dissolves to form a colourless solution

Question 9

CaCO3+CO2+H2O=

Answer 9

Ca(HCO3)2

Question 10

What does carbon dioxide form when it reacts with water?

Answer 10

-Forms a weak acid, carbonic acid

Question 11

CO2+H2O=

Answer 11

H2CO3

Question 12

What are 4 physical properties of oxygen?

Answer 12

• Colourless, odourless gas
• Slightly soluble in water
• Slightly denser than air
• Diatomic O2

Question 13

How is oxygen made?

Answer 13

Using hydrogen peroxide and manganese(IV) oxide. Manganese(IV) oxide is a catalyst which is used to speed up the decomposition of hydrogen peroxide

Question 14

2H2O2(Hydrogen peroxide+ Manganese(IV)oxide=

Answer 14

2H20+O2

Question 15

What is the test for oxygen?

Answer 15

Glowing splint relights in the presence of oxygen

Question 16

What is electrolysis?

Answer 16

The decomposition of a liquid electrolyte using a direct current of electricity

Question 17

What is the electrolyte?

Answer 17

The liquid or solution that conducts electricity and is decomposed by it

Question 18

How can you test if a liquid conducts electricity?

Answer 18

Two graphite rods are placed in a liquid and connected externally to a power supply such as a battery or a power bank

Question 19

If a liquid conducts electricity and is decomposed by it what takes place?

Answer 19

Electrolysis

Question 20

What are cations?

Answer 20

Positive ions

Question 21

What are negative ions called?

Answer 21

Anions

Question 22

Why do electrolytes conduct electricity?

Answer 22

As they have free ions that can move and carry charge

Question 23

What do the positive(cations) and negative(anions) move to when they are free?

Answer 23

• Cations move to the negative electrode(Cathode)

- Anions move to the positive electrode(Anode)

Question 24

What do the positive ions gain when at the negative electrode?

Answer 24

Gain electrons to become atoms. =Reduction

Question 25

What do negative ions lose when at the positive electrode?

Answer 25

Lose electrons to become atoms=Oxidation

Question 26

What are the 2 most common electrolytes?

Answer 26

- Molten ionic compounds | - Aqueous ionic compounds

Question 27

What ions does a molten ionic compound contain?

Answer 27

Free ions that move and carry charge

Question 28

What ions does Lead(II) Bromide contain?

Answer 28

- Cation =Lead(II), Pb2+ | - Anion= Bromide, Br-

Question 29

Pb2+ + 2e- =

Answer 29

Pb

Question 30

What is the positive ion Pb2+ attracted to?

Answer 30

Cathode (-ve electrode)

Question 31

What is observed when Pb2+ + 2e-

Answer 31

Silvery grey liquid formed, which sinks to the bottom

Question 32

What is negative ion Br- attracted to?

Answer 32

Anode(+ve electrode)

Question 33

2Br- =

Answer 33

Br2 + 2e-

Question 34

What is observed when Br- is attracted to anode?

Answer 34

Red-Brown pungent gas evolved

Question 35

what are the 5 steps to make iron?

Answer 35

1 coke burns in oxygen to produce carbon dioxide 2 carbon dioxide reacts with more coke to produce the reducing agent which is carbon monoxide 3 iron(111) oxide reacts with carbon monoxide to produce molten iron and carbon dioxide 4 calcium carbonate thermally decomposes to form calcium oxide and carbon dioxide 5 acidic silicon dioxide impurities react with calcium oxide to form molten slag sorryyyyy should of made separate cards oops

Question 36

what is a reversible reaction?

Answer 36

one where reactants can change into products and the products can change back into reactants visualise the symbol cuz i can’t type it :)

Question 37

what is dynamic equilibrium ?

Answer 37

when the rate of the forward reaction is equal to the rate of the reverse reaction and the amounts of reactants and products remain constant

Question 38

learn test for water cuz i can’t rlly type the sign and shit for equilibrium

Answer 38

beep boo beep

Question 39

what will happen if copper 11 sulfate ( CuSO4.5H2O) is heated to constant mass?

Answer 39

it will loose water and become anhydrous

Question 40

what is the empirical formula?

Answer 40

the simplest whole number ratio of atoms of each element in a compound

Question 41

what is the molecular formula ?

Answer 41

the actual number number of atoms of each element present in a compound

Question 42

How do you calculate moles?

Answer 42

MASS➗Mr

Question 43

How do calculate concentration (mol/dm3)

Answer 43

- moles➗Volume(dm3)