Chemistry

Question 1

describe diamond

Answer 1

• each carbon make 4 covalent bonds

- used in cutting tools and jewelry

Question 2

describe graphite

Answer 2

• each carbon makes 3 bonds
• arranged in layers which can slide
• one electron from each atom is delocalised so is good conductor

Question 3

alkali metal + water —

Answer 3

metal hydroxide + hydrogen

Question 4

alkali metal + oxygen —

Answer 4

metal oxide

Question 5

state the use for argon

Answer 5

filament lamps

Question 6

state use for helium

Answer 6

floating balloons

airships

Question 7

what is a metal ore ?

Answer 7

rock with enough metal to make it economically viable to extract

Question 8

what are the 3 ways to extract a metal from its ore ?

Answer 8

• reduction with carbon
• electrolysis
• displacement reaction

Question 9

how are metals extracted by reduction with carbon ?

Answer 9

react with carbon (smelt), oxygen will bond with the carbon

only works with less reactive metals than carbon

Question 10

why is copper extracted by reduction not used for electrical wiring ?

Answer 10

this method makes impure copper, reducing the conductivity

Question 11

how does electrolysis work ?

Answer 11

• compound dissolved in water conducts (electrolyte)

- ions go to the electrodes and gain / lose electrons to become atoms

Question 12

what is the negative electrode called ?

Answer 12

cathode (gives electrons)

Question 13

what is the positive electrode called ?

Answer 13

anode (accepts electrons)

Question 14

when is electrolysis used ?

Answer 14

• high profits (expensive process)

- metal is more reactive than carbon

Question 15

describe the properties / uses of copper

Answer 15

• good conductors so electrical wires
• hard but can be bent
• can’t react with water (less reactive than hydrogen)

Question 16

describe the properties / uses of aluminium

Answer 16

• corrosion-resistant and low density
• forms hard alloys
• used in planes

Question 17

describe the properties / uses of titanium

Answer 17

• corrosion-resistant, low density, very strong

- replacement hips

Question 18

why are alloys generally harder ?

Answer 18

different sized atoms make it harder to slide past each other

Question 19

what is crude oil ?

Answer 19

a mixture of hydrocarbons

Question 20

what is an electrophile ?

Answer 20

electron pair acceptor

Question 21

what is a nucleophile ?

Answer 21

electron pair donor

Question 22

what is the most common example of electrophilic addition ?

Answer 22

alkene and bromine

orange bromine water to colourless

Question 23

how do you name a polymer ?

Answer 23

poly (monomer name)

Question 24

what is nomenclature ?

Answer 24

naming organic compounds

Question 25

what is the 'dripping' equipment used in titration called ?

Answer 25

burette

Question 26

what does volatile mean ?

Answer 26

easily evaporated

Question 27

what is a monoprotic acid?

Answer 27

gives one H+ per molecules when dissociates (hydrochloric acid)

Question 28

what is a diprotic acid?

Answer 28

gives two H+ (sulfuric acid)

Question 29

what is a triprotic acid?

Answer 29

gives 3 H+ (phosphoric acid)

Question 30

what is the relationship between conductivity and weak/strong acids ?

Answer 30

the stronger the acid, the more conductive it is due to increased conc of ions

Question 31

give the method for making insoluble salts

Answer 31

- mix two soluble salts | - filter, wash, dry

Question 32

give the method for making soluble salt from insoluble base and acid

Answer 32

- react until all acid has been neutralised | - filter, crystalise salt

Question 33

give method for making soluble salt from soluble base (alkali) and acid

Answer 33

- neutralise acid by titration | - warm salt solution to get crystals

Question 34

metal + acid ---

Answer 34

salt + hydrogen

Question 35

what is a disproportionate reaction ?

Answer 35

element is both oxidised and reduced in same reaction

Question 36

what is the equation for iron rusting ?

Answer 36

Iron + oxygen + water --- hydrated iron(|||) oxide

Question 37

name 5 ways to prevent iron from rusting

Answer 37

- make alloys - oiling/greasing/painting - galvanise (coated in thin layer of zinc) - sacrificial protection (covered by more reactive metal)

Question 38

Q =

Answer 38

mc delta T

Question 39

what is the specific heat capacity of water ?

Answer 39

4.2

Question 40

bond breaking is an ... process

Answer 40

exothermic

Question 41

bond making is an ... process

Answer 41

endothermic

Question 42

what does Haber process make ?

Answer 42

ammonia from nitrogen and hydrogen

Question 43

where is the nitrogen and hydrogen (used in Haber process) from ?

Answer 43

nitrogen - fractional distillation of liquid air | hydrogen - natural gas

Question 44

what are the conditions for Haber process ?

Answer 44

iron catalyst 200 atm 450C

Question 45

give the flame test method

Answer 45

- dip a wire in HCl and rinse with distilled water | - dip in sample and put in blue flame

Question 46

whats the test for chlorine ?

Answer 46

will bleach damp litmus paper

Question 47

what is the test for halides ?

Answer 47

add silver nitrate, will form a coloured precipitate

Question 48

what is the test for sulfates ?

Answer 48

add barium chloride, will form white precipitate

Question 49

Rf =

Answer 49

distance by compound / distance by solvent

Question 50

what is an electrolyte ?

Answer 50

liquid that contains ions and can conduct electricity

Question 51

how is methanol dangerous ?

Answer 51

toxic + can cause blindness if consumed

Question 52

how is ethanol dangerous ?

Answer 52

can cause damage to liver and brain

Question 53

are alcohols miscible ?

Answer 53

small carbon chains are, solubility decreases as chain length increases

Question 54

what is formed when alcohols react with sodium ?

Answer 54

hydrogen and alkoxides

Question 55

state the uses of ethanol

Answer 55

- solvent (perfumes) - fuel (spirit burners) - can be mixed with petrol -

Question 56

Ethanol + oxygen ---

Answer 56

ethanoic acid + water

Question 57

ethanoic acid + sodium carbonate ---

Answer 57

sodium ethanoate + water + CO2

Question 58

what is electroplating ?

Answer 58

process of coating a metal with another using electrolysis

Question 59

for electroplating, what are the anode, cathode and electrolyte ?

Answer 59

anode - the outer metal cathode - the inner metal electrolyte - outer metal salt solution

Question 60

what is a separating funnel used for ?

Answer 60

separating immiscible liquids

Question 61

what is fractional distillation ?

Answer 61

separating a liquid mixture into different parts (fractions) due to difference in boiling points

Question 62

what is soft water ?

Answer 62

water that contains no calcium/magnesium ions

Question 63

what is difference between permanently and temporarily hard water ?

Answer 63

Mg and Ca ions can be removed from temporarily by boiling

Question 64

state two ways of changing hard water to soft

Answer 64

- add washing soda (sodium carbonate) | - pass through ion exchange column

Question 65

what is a hydrogen fuel cell ?

Answer 65

hydrogen reacts with oxygen (without burning) to produce water - energy is released from reaction