Chemistry Stuff

Question 0

Displacement of metals from their salts

Answer 0

Any metal will displace another below it in the reactivity series from a solution of one of its salts

Question 1

Hydrogen displacement

Answer 1

Can be displaced from an aqueous solutions
The solution is an acid

Metals above hydrogen in the reactivity series can displace hydrogen gas from dilute hydrochloric/ sulfuric acid

Question 2

Salts of metals

Answer 2

Chlorides, nitrates, sulfates

Question 3

Chlorides

Answer 3

Soluble on waer except silver chloride and led (iii) chloride

Question 4

Nitrates

Answer 4

Soluble in water

Question 5

Sulfates

Answer 5

Soluble in water

except barium sulfate, calcium sulfate and lead (ii) sulfate

Question 6

Reduction

Answer 6

Oxygen removed from a metal oxide

Question 7

Reducing agent

Answer 7

A substance that carries out the reduction

Question 8

Reduction of a metal oxide

Answer 8

Heating the metal oxide with a more reactive metal

Question 9

Carbon in reduction

Answer 9

Can reduce some metal oxides into metals

Carbon becomes carbon dioxide

Question 10

Combustion of hydrogen

Answer 10

Hydrogen burns when heated in air or oxygen

Forms water

Question 11

Test for hydrogen

Answer 11

Put a lighted splint at the mouth of a test tube, a squeaky pop will be heard if hydrogen is present

Question 12

Test for water

Answer 12

Add the liquid to anhydrous copper (ii) sulfate
The white powder will turn blue if pure water is present
Copper (ii) sulfate formed

Boils at 100C freezes at 0C

Question 13

Sacrificial protection of iron

Answer 13

Zinc is more reactive than iron

Even if the iron is scratched the iron is still protected because the zinc reacted and corrodes instead of the iron.

Question 14

Galvanised iron

Answer 14

Iron coated in zinc

Question 15

Preventing steel and iron rusting

Answer 15

Can be prevented by preventing contact with water and oxygen

Can be done by orating in: grease, oil, paint, plastic, a less reactive metal

Question 16

Problems of coating to prevent rusting

Answer 16

Once the coating is scratched/washed away the iron is once again exposed to water and oxygen and will rust

Question 17

Rusting of iron

Answer 17

Iron+ water+ oxygen

Iron —> iron (iii) due to loss of electrons

Question 18

Speeding up rusting

Answer 18

By having electrolytes in the water

Question 19

More reactive the hydrogen metals

Answer 19

React with both: dilute hydrochloric acid and dilute sulfuric acid
Form a salt and hydrogen

Question 20

magnesium+ HCl / H2SO4

Answer 20

Bubbles
Disappears
Mixture gets hot
Colourless solution formed

Question 21

Aluminium+ HCl / H2SO4

Answer 21

Bubbles when heated
Disappears
Colourless
Solution formed

Question 22

Zinc+ HCl / H2SO4

Answer 22

Bubbles
Disappears
Colourless solution formed

Question 23

Iron+ HCl / H2SO4

Answer 23

Bubbles
Disappears
Pale green solution formed

Question 24

Presence of carbon dioxide

Answer 24

Limewater turns milky

Question 25

Carbon dioxide absorbs

Answer 25

infra red

Question 26

Acid rain

Answer 26

Rain with a below 6 PH leaches vital vitamin out of the soil- kills trees Lowers the PH of lakes so that fish can't live in it Weathers building made of; limestone, marble, iron

Question 27

Laboratory preparation of carbon dioxide

Answer 27

Metal carbonate + an acid = carbon dioxide | Calcium carbonate most often used

Question 28

Laboratory preparation of oxygen

Answer 28

Hydrogen peroxide decomposes slowly and forms water and oxygen Decomposition sped up by adding the catalyst solid manganese dioxide

Question 29

Finding oxygen using iron

Answer 29

Place wet iron fillings at the end of a burette Water rises up the burette Due to iron reacting with air Percentage of oxygen = ( volume of oxygen used/volume of air at start ) x 100

Question 30

Finding oxygen - copper

Answer 30

Aparratus with 100cm^3 of air Heat copper at one end of the silica tube Pass air over the copper Keep heating fresh copper Stop heating when gas in the servings stops decreasing Final volume of air left should be 79cm^3 21cm^3 has reacted

Question 31

Nitrogen in air

Answer 31

78%

Question 32

Oxygen in air

Answer 32

21%

Question 33

Argon in air

Answer 33

0.9%

Question 34

Carbon in air

Answer 34

0.04%

Question 35

Group 7

Answer 35

Halogens Non-metals Poisonous React with metals and form salts

Question 36

Three halogens

Answer 36

Chlorine Bromine Iodine

Question 37

Chlorine room temperature

Answer 37

Gas | Green

Question 38

Bromine room temperature

Answer 38

Liquid | Red-brown

Question 39

Iodine room temperature

Answer 39

Solid | Black

Question 40

Group number

Answer 40

Number of electrons in outer shell

Question 41

Same group

Answer 41

Same chemical properties

Question 42

Periodic group left to right

Answer 42

Increasing atomic number | Periods

Question 43

Top to bottom

Answer 43

The more shells | Groups

Question 44

Group 1

Answer 44

``` More reactive the further down you go Very reactive metals Stored under oil so they can't react with water/oxygen Alkali metals React with water form alkaline solutions ```

Question 45

Group 1 characteristics

Answer 45

``` Good conductors Very soft Low melting/ boiling points Low densities Shiny surface (dull after reacting with oxygen) Burnt in air/oxygen Form white, solid oxides ```

Question 46

Group 8/0

Answer 46

Noble gases Chemically unreactive Neither lose or gain electrons easily