Chemistry paper 1

Question 1

Definition of a compound

Answer 1

Two or more elements which are chemically combined in fixed proportions.

Question 2

Describe Thomson model of the atom.

Answer 2

A positive charge with a spherical shape with embedded electrons.The plum pudding model.

Question 3

Describe John Dalton’s theory of the atom.

Answer 3

Solid spheres different spheres made different elements.

Question 4

what did Ernest Rutherford and Ernest Marsden do to prove the PPM wrong?

Answer 4

Fire alpha particles at a sheet of gold.Some were deflected instead of all of them passing straight through.

Question 5

Describe Ernest Rutherford theory of the atom.

Answer 5

Tiny positive charge (where most of the mass is concentrated) at the centre surrounded by electrons(Mostly empty space).The nuclear model.

Question 6

What did Neils bhor suggest to the Nuclear model of the atom and why?

Answer 6

Electrons orbit in fixed positions (shells)

Because if they weren’t they would be attracted to the nucleus and collapse.

Question 7

who discovered the existence of neutral particles.

Answer 7

James Chadwick

Question 8

List three properties for G1 elements.

Answer 8

• One outer electron
• Low boiling and melting point decrease as you go down the group
• Become more reactive down the group

Question 9

what are the G! elements known as?

Answer 9

Alkali metals

Question 10

What is formed with a G1 element and water?

Answer 10

Alkali metal + water -> Metal hydroxide + hydrogen.

Question 11

What is formed when G1 elements react with non-metals?

Answer 11

Ionic compounds

Question 12

What are G7 elements known as ?

Answer 12

Halogens

Question 13

What do the atoms in the halogens consist of?

Answer 13

Molecules

Question 14

What happens to the reactivity of G7 elements and why?

Answer 14

Reactivity decreases as you go down because harder to gain electrons when further from the nucleus.

Question 15

What do Halogens form when reacting with metals?

Answer 15

Ionic salts

Question 16

what are group 0 elements known as ?

Answer 16

Noble gases

Question 17

What is the reactivity of G0 elements?why?

Answer 17

Very unreactive because they have a full outer shell of electrons.

Question 18

What does the change of state depend on?

Answer 18

Amount of energy needed to overcome forces of attraction between particles

Question 19

What type of attraction does an ionic bond have

Answer 19

electrostatic between negative and positive ions

Question 20

Define delocalised.

Answer 20

Electrons are not bound to one atom

Question 21

What type of attraction does a metallic bond have?

Answer 21

Electrostatic forces between positive ions and electrons

Question 22

List properties of a metal

Answer 22

High melting and boiling.
Good conductors.
Ductile.
Malleable.

Question 23

what happens as simple molecular forces get bigger and why?

Answer 23

Bp and Mp incr. molecules get bigger so more inter molecular forces so more energy needed to break the bonds.

Question 24

Describe structure of diamond

Answer 24

Carbon atoms form four strong covalent bonds.

Rigid giant covalent structure.(very hard)

Question 25

Describe the structure of graphite.

Answer 25

Each carbon atoms form three covalent bonds Makes layers of hexagons. Layers are held together weakly because no covalent bonds.ifm Layers slide over each other making it soft and slippery. Delocalised electrons make it a good conductor

Question 26

Describe the structure of graphene

Answer 26

``` Sheet of carbon atoms arranged in a hexagon. one atom thick Covalent bonds make it strong. Is very light conduct electricity ```

Question 27

What is a fullerene. Talk about it's structure.

Answer 27

Molecules of carbon.Shaped liked closed tubes or hollow balls can be formed from hexagons but other rings as well.

Question 28

Name three uses of fullerenes.

Answer 28

Drug delivery. catalyst. Lubricants.

Question 29

The mnemonic for the reactivity series. | Philip Scofield Loves Calling Me a Crazy Zombie. I Hate Cats.

Answer 29

``` Potassium. Sodium. Lithium. Calcium. Magnesium. Carbon. Zinc. Iron. Hydrogen. Copper. ```

Question 30

Name 4 acids and their pH.

Answer 30

Car battery/stomach acid-1 Vinegar, lemon juice-3 Acid rain-4 Normal rain-5

Question 31

The word equation for neutralisation

Answer 31

acid + base -> salt + water

Question 32

what ions do acids or alkali for in water

Answer 32

acid-H+ | alkali-OH-

Question 33

what is the difference between weak and strong acids?

Answer 33

weak acids partially ionise in water | strong acids completely ionise in aqueous solutions

Question 34

what position does the equilibrium lie on in the ionisation of a reversible reaction and why?

Answer 34

Left because only a few acid particles release H+ ions.

Question 35

name 3 bases.Which one produces co2?

Answer 35

metal oxide, hydroxide, carbonate-co2

Question 36

why should electrodes be made of inert material?

Answer 36

so they don't react with the electrolyte

Question 37

what is used to lower the melting point of aluminium oxide?why?

Answer 37

cryolite because it reduces costs because high boiling points mean lots of energy and that is expensive

Question 38

what is produced at the cathode of electrolysis of aq solout.

Answer 38

- hydrogen if metal forms element more reactive that H | - pure metal formed around cathode if less reactive than hydrogen

Question 39

what is produced at the anode of electrolysis of aq solout

Answer 39

- if OH- and halide ions present then cl,br or io will form | - if no halide ions present then oxygen and water will be produced

Question 40

the half equation for if no halide ions are present

Answer 40

4OH-->o2+2h^2,o+4e