AS paper 1

Question 1

how to make formulas

e.g, ammonium sulfide

Answer 1

.write out ions of each part and find the ratio between the two

e.g.
ammonium = NH4 +
sulfide = S 2-

Ratio = 2:1
–> (NH4)2S

Question 2

how to find out if an equation is a neutralisation reaction

Answer 2

the base/alkali accepts an H+ ions

Question 3

how to find the number of obritals in an atom

Answer 3

s subshells = 1 orbital
p subshells = 3 orbital
d = 5

Question 4

how to determine which electron configuration has the highest ionisation energy

Answer 4

bigger up and across

Question 5

carbonate(CO3) + acid(OH) –>

Answer 5

salt + H2O + CO2(effervescence)

Question 6

how to calculate enthalpy changes of combustion (ΔcH)

Answer 6

.write out equation
.write out XCO2 + XH2O below
.draw two down arrows
.plug in (ΔcH)
.flip the figure for the right arrow

Question 7

what are structual isomers

Answer 7

they have same molecular formula

Question 8

what is a propagation step

Answer 8

.step where radicals react with non-radicals to form new radical and non- radical

.H always comes off to form a non-radical with the old radical

Question 9

electrophillic is when…

Answer 9

the thing being added/subsituted is delta positive(bond to outside atom)

nucleophillic = delta negative(outside atom to big one)

Question 10

how to find percentage error

Answer 10

uncertainity/mass x100 =%

Question 11

modification to reduce percentage error in mass

Answer 11

.have a larger mass

Question 12

what is the reagent needed for halide ion tests

Answer 12

silver nitrate

chloride = white percipitate
bromine = cream
iodine = yellow

Question 13

how to calculate enthalpy change of reaction(ΔrH)

Answer 13

.first use Q = mcΔT

Q = quantity of heat transfered(J)
m = total mass of solutions
c = specific heat capacity of water(in data sheet)
ΔT = temp change

.then use ΔH(J) = Q/n
.convert to KJ mol-1(divide by 1000)

n = moles of limiting reactant

.ΔH = - if heat increases and + if heat decreases

Question 14

Le Chatelier’s principle

Answer 14

Temp-
.if forward reaction = exo(-ve) = lowering the temp = equilibrium will move to raise temp = move to exothermic direction = forward

pressure-
.more gaseous moles on the products = increasing the pressure = equilibrium will move to reduce pressure move to fewer gaseous moles = foward

Question 15

how to determine Kc

Answer 15

.[products]^big num/[reactants]^big num

[] = conc

Question 16

reagents and conditions for alkenes –> alkane

Answer 16

H2 + metal catalyst

Question 17

alcohol —> alkene (reagents and conditions)

Answer 17

concentrated H2SO4 heat

Question 18

alcohol -K2Cr2O7/H2SO4–>

Answer 18

primary- distilled = aldehyde, reflux = carboxylic acid

secondary- reflux = ketone

Question 19

how to do atom economy %

Answer 19

usefull mass of product/total mass of product

Question 20

how to detemine if a compound is polar

Answer 20

.central atom has lp
.or atoms around the central atom are different

Question 21

how to determine which organic compound has the highest boiling point

Answer 21

.longest straight chain and least amount of branching

Question 22

alkene + water/steam –>

Answer 22

alcohol

.needs acid catalyst

Question 23

how to find the ionisation energy for one ion

Answer 23

1st ionisation energy/6.02 x 10^23

Question 24

how to draw boltzmann distribution model

Answer 24

.no. of paritcle = y axis
.energy = x axis
.dont touch x axis at the end
.Ec drawn behind Ea

Question 25

how catalyst reduce energy demand and benefits enviroment

Answer 25

.requires less temp
.less fossil fuels are formed

Question 26

exothermic/endo

Answer 26

exo - more energy is used to break bonds
endo - more energy is released to form bonds

Question 27

how to find num of atoms of a element in a compound

Answer 27

.times number of moles by the small number at the front of the element
.times that by 6.02 x10^23

Question 28

what is moles of gas in RTP

Answer 28

vol in cm3/24000

Question 29

how to obtain a insolublue salt

Answer 29

.filter off
.and dry

Question 30

alcohol + H2SO4 + heat

Answer 30

alkene

Question 31

trend of boiling points for halogens

Answer 31

.number of electrons increases down the group
.all have London forces
.stronger london forces down the group

Question 32

how to test for halides and ammonium ions

Answer 32

.halides-
.add silver nitrate =precpitate = white for chloride, cream for bromide and yellow iodine

Ag+ + Br- –> AgBr

ammonium- heat with a hydroxide which dosent contain ammonia = damp red litmus paper turns blue

NH4+ + OH- –> NH3 + H2O

Question 33

how to determine the conditions to get maximum equilibrium

Answer 33

.more gaseous moles on right/left = wants high/low pressure

.foward reaction exo/endo = wants low/high temp

Question 34

standard conditions for standard enthalpy

Answer 34

298K
100 kPa

Question 35

What is meant by concordant titres?

Answer 35

titres that are 0.1cm3 apart from each other

Question 36

the two routes to form Ba(OH)2

Answer 36

.add water to Ba
.Ba + 2H2O –> Ba(OH)2 + H2

.add oxy to Ba
.2Ba + O2 –> BaO
.BaO + H2O –> Ba(OH)2

Question 37

Explain, using Boltzmann distributions, why increasing the temperature and using a catalyst
both increase the reaction rate

Answer 37

look at photo on phone

Question 38

what is meant by the term: homologous series

Answer 38

.similar chemical properties but differ by CH2

Question 39

Plan an experiment on a test tube scale that would show the trend in the reactivity of the
halogens Cl 2, Br2 and I2.

Answer 39

.mix halogen and halide

chlorine-
mixed with bromide and turns yellow

bromine-
mixed with iodide and turn purple

iodine-
no change

Cl2 + 2Br- –> Br2 + 2Cl-

reactivity decreases down the group