Important]

Question 1

when working out pv nrt what do you need to remember about the moles

Answer 1

Make sure you account for all the moles so on the left if theres 2 but on the right hand side theres 5 moles make sure you divide by 2 to get one mole and times it by 5. Bc you need the moles of all the gases

Question 2

What species is the best reducing agent

Answer 2

Best at losing electrons so you look at negatively charged ions so theyd want to lose electrons more than like normal diatomic atoms because their negative so want to lose electrons lose choc becoming positive. So the bigger negatively charged ion

Question 3

Cracking- thermal and catalytic number

Answer 3

Cat- around ~450 and thermal around 1000 cat zeolite and thermal high pressure as well alkenes and shorter alkanes cat= aromatic compounds and fuels

Question 4

Suggest a reason for the difference between the exp value and the correct value

Answer 4

Failutre to heat for long enough

Question 5

How to make it more accurate

Answer 5

Heat to a constant mass, to ensure that all the water has been driven off

Question 6

Define the term relative molecular mass

Answer 6

The sum of average masses of atoms in formula/ 1/12 mass of an atom of 12C

Question 7

If it asks you to work out the relative molecular mass of something what does it want you to work out

Answer 7

Its mr

Question 8

Catalyst and condition for catalytic cracking

Answer 8

around 450 degrees zeolite catalyst slight pressure makes aromatics and fuels

Question 9

Explain with reference to intermolecular forces why distillation allows propanal to be sep from the other organic compounds on this mixture

Answer 9

As propanal has dipole dipole forces between molecules alcohol and cooh have hydrogen bonding so the forces between mols in the aldehydes are weaker so would evap first

Question 10

M/z for like mass spec. Is the same as?

Answer 10

The mr

Question 11

cracking and conditions for thermal

Answer 11

around 1000 degrees high pressure makes alkenes

Question 12

fermentation

Answer 12

c6h12o6–> 2ch3ch2oh +2h20 yeast anaerobic temp 30-40. cheap sugar renewable but batch process yield isnt pure needs distilling

Question 13

hydration of ethene

Answer 13

c2h4+h20–> c2h5oh 100 percent pure continuous process. ethene is non renewable

Question 14

give one reaosn why bonds in molecules such as carbon dioxide and 111-trifluoromethane absorb infrared radiation

Answer 14

bc bonds vibrate

Question 15

when talking abotu intermolecular forces wgah what shuood you write

Answer 15

BETWEEN MOLECULES

Question 16

how does dehydration work

Answer 16

just take off a h20, from where the oh is take that off, then take off a hydrogen from an adjacent carbon and then a double bond also forms there. `

Question 17

how do you name a molecule if there is a alcohol and a alkene

Answer 17

propeno enol or buten-3-ol whatever

Question 18

how to measure out 50g of water

Answer 18

water has a density of 1gcm-3, so 50cmcubed could be measured out

Question 19

if your doing empirical and the number isnt roundable, so within 0.1 away from the next whole number

Answer 19

times it till it is
0.25= times it by 4
0.33= times by 3
0.50= times by 2
be careful

Question 20

what if the mr of a molecule is exactly the same as the empirical formula mass

Answer 20

the molecular formula is the same as the empirical

Question 21

difference between nitrates and nitrites

Answer 21

nitrates are no3 nitrites are no2

Question 22

what state is iron 3 oxide

Answer 22

solid

Question 23

what is the rate or rate constant units

Answer 23

mol dm-3 s-1

Question 24

activation energy in arrhenius unit conversions

Answer 24

when you work it out its in joules. then divide by 1000 to get it into kj

Question 25

Describe how a student could distinguish between aqueous solutions of
potassium nitrate, KNO3, and potassium sulfate, K2SO4, using one simple
test-tube reaction.
[3 marks]
Reagent
Observation with KNO3(aq)
Observation with K2SO4(aq

Answer 25

BaCl2 / Ba(OH)2 / Ba(NO3)2 / BaX2 or names
colourless
white precipitate / white solid

Question 26

Describe how a student could distinguish between aqueous solutions of
magnesium chloride, MgCl2, and aluminium chloride, AlCl3, using one simple
test-tube reaction.
[3 marks]
Reagent
Observation with MgCl2(aq)
Observation with AlCl3(aq)

Answer 26

NaOH / sodium hydroxid

white precipitate / white solid 1
white) ppt which dissolves in excess (NaOH