Question 1 – |
Question | Answer | Marks Available |
1.1. Draw the displayed formula for ethanoic anhydride | 
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1.2. Why did the condenser need to be filled with water in at the bottom and coming out at the top | So the vapours are cooled to become liquid. So that the entire jacket is filled with water. For efficient condensation. |
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1.3. Why was neither bung nor thermometer added at top of flask? | So there is no pressure buildup |
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Why is ethanoic anhydride used instead of ethanoyl chloride. Give 2 reasons Do not mention cost |
Easier to store |
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Why is water a suitable solvent in terms of aspirin solubility? |
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| 34.9cm^3? Around 78.8%? | 5 |
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conventional representation of cell (standard hydrogen electrode) to calculate Zn cell | Pt (S) | H2 (g) | H+ (aq) II Zn2+(aq) I Zn (s) | 1 |
state one purpose of salt bridge | completes circuit Allows ions to flow | 1 |
| Mg + Cu2+-> Mg2+ + Cu | 1 |
Why is KNO3 be used as salt bridge |
It is conductive | 1 |
Unknown liquids, propan-1-ol, propanal and propanoic acid. How do you prepare the tests, observations and equations for the tests | Sodium hydrogencarbonate->Co2 produced so effervescence, if limewater available in lab collect gas using gas syringe, bubble through it should get cloudy white/milky white, for propanoic acid, nvc for rest.
Add dilute H2SO4 to the potassium dichromate to prepare acidified potassium dichromate. Add potassium dichromate to the test tubes, propanal and propan-1-ol colour change from orange to green, the propanoic acid will remain orange.
Add tollens reagent to all three test tubes, take new samples and then propanal test tube should display a silver mirror, nvc for rest.
I cba to type out equations CH₃CH₂COOH + NaHCO₃ → CH₃CH₂COONa + CO₂ + H₂O
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Standard conditions q | 1.00 moldm^-3 all solutions, 298K, 100kpa | 1 |
Question X – Titration Practical |
Titration practical 1-add sulfuric acid to magnesium 2- add distilled water up to 250cm 3-add 25cm to a flask 4- titrate with NaOH solution 5-get a mean titre | 1- use __ measuring cylinders to measure out 100cm of H2SO4 and weigh weighing boat before and after adding Mg 2-fill up to 250 in a conical flask, rinsing the sides. Add a stopper and invert to mix 3- use a pipette to transfer 25cm to a conical flask and add an indicator 4- add NaOH solution to burette, ensuring no air bubbles and reading from the miniscus 5- create a mean of concordant results | 6 |
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It defo said TOTAL uncertainty was 0.15 | 1 |
draw the 3D structures of the two alcohols | ? Diffracted? | 5 |
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Write the equation showing ethylamine acting as a base when add H2Ofor | CH3CH2NH2 + H2O <-> CH3CH2NH3+ + OH- | 2 |
Why ethylamine stronger base than ammonia | I swear this is not meant to be on spec anymore because it was proven false Akyl groups electron releasing make the lone pair on the N atom more available | 3 |
Write equation for reaction of bromo-ethane with XS ethylamine | CH3CH2Br + 2CH3CH2NH2 -> CH3CH2NHCH2CH3 + CH3CH2NH3Br
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Given: 1 = acid, 2 = base, 3 = free radical, 4=nucleophile , 5=electrophile , 6 = catalyst |
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Section B: MCQ (25/30 accounted for) |
Infrared graph, determine which molecule it is |
Butanoic acid | 1 |
What is the formula of the compound containing CoCl2(N2H4)x | C
CoCl₂(N₂H₄)₂ | 1 |
Which is the correct statement regarding fractional distillation | Kerosine is a mixture (not that it was the most viscous cuz there was residue below it Residue is not a fraction, it was viscous How did u even get this pic ???? It’s from an older paper or an AS one idk it was on PMT no wayyy aqa was bored asl I cant believe theyve just reused some of them 
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Which has the atoms all in the same plane |
C₆H₅Cl
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Which process requires the largest energy |
He⁺ → He²⁺ + e⁻ | 1 |
Which statement is true about cracking |
Thermal cracking produces alkenes | 1 |
which atom has more protons than neutrons |
³He | 1 |
which fact is true about terylene | it’s a polyester | 1 |
Which of these are able to form hydrogen bonds | Kevlar (because its polyamide) | 1 |
Which is true about phenylamine | To make dyes | 1 |
Which of these molecules has delocalised electrons? | Strontium (metallic bonding) | 1 |
Which of these are formed from hydrolysis of phenyl methyl ethanoate | C₆H₅CH₂OH | 1 |
Which acid has pH<1 | Sulfuric Acid H2SO4 (diprotic) | 1 |
Which will happen if concentration increases | More reactant particles per same volume - Frequency of collisions increases
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enthalpy change calculation | D
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Which of these statements about a maxwell-boltmann graph is true | Few particles have very high energy | 1 |
Zwitterion question (idk name) | A The first one as charges cancel out | 1 |
Which of these statements about enzymes are not correct | enzymes are complementary to both optical isomers of a compound
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How many Hydrogen bonds between the correct DNA bases | 3 H bonds between C and G | 1 |
What type of polymer is terylene | Polyester | 1 |
