N5 Chemistry

O

Innocent smooth juice:

  • 22 mg/100ml

  • https://www.innocentdrinks.co.uk/things-we-make/juices

Tesco juice:

  • 30 mg/100ml

  • https://www.tesco.com/groceries/en-GB/products/255595843

Tropicana:

  • 28 mg/100ml

  • https://www.tropicana.co.uk/juice/orange-smooth

Supporting information

Oxidation: https://www.bbc.co.uk/bitesize/guides/zyq22hv/revision/4

Redox: https://www.bbc.co.uk/bitesize/guides/ztkdd2p/revision/5

Procedure:

  1. Rinse 25cm3 pipette with orange juice sample 1.

  2. Pipette a 25cm3 orange juice into a conical flask.

  3. Add ~1cm' of 1% starch solution and 150cm3 of distilled water to the conical flask

  4. Rinse a 50cm3 burette with a little 0.005molL-1 iodine solution

  5. Fill the burette with 0.005molL-1 iodine solution.

  6. Place the conical flask containing the vitamin C sample directly underneath the burette and record the initial reading on the burette.

  7. Add the iodine solution from the burette into the conical flask with swirling and continue adding it until the first permanent trace of a dark blue-black colour appears.

  8. Record the final reading on the burette.

Solubility in water

  • polar

  • Hydroxyl groups

Explain why atoms decrease in size going from lithium to neon.

  • Increase in nuclear charge

Electronegativity

  • attraction an atom/nucleus has for the bond/shared electrons.

Explain why electronegativity values of the halogens decrease going down the group.

  • Increased screening.

  • attraction of the nucleus/protons for the electron(s) decreases

Explain fully why the ionic radius of sulfur is greater than the ionic radius of sodium.

  • Na forms Na+ or loses electrons to form an ion, and S forms S2− or gains electrons to form an ion.

  • Sodium ion has one less energy level than sulfur ion or sulfur ion has one more energy level than sodium ion.

Explain fully why second ionisation energy is much greater than the first ionisation energy for Group 1 elements.

  • Second ionisation energy involves removal of an electron from an electron shell that is inner/full

  • The second electron is less screened

Explain why an excess is used

  • To ensure all of the other reactants are used up

Dynamic equilibrium

  • The rate of the forward reaction equals the rate of the reverse reaction

Diagrams:

  • Passing a gas through a liquid

  • Passing a gas through a solid

  • Gas collection x2

  • Pipette

  • Burette

  • Volumetric flask

  • Filtration

  • Evaporation

  • Distillation

  • Condenser x2

  • Esterification/condensation

  • Steam extraction

  • Isoprene chemical structure and systematic name

Procedure

  • How to weigh out 2 g of NaCl? (Using a balance)

  • How to standard solutions are prepared?

  • How to use pipettes/burettes

  • Test for degree of unsaturation of oils

  • Test for viscosity

Why deionised water

Why hot water bath

Explain the change in equilibrium

Explain what happen when protein is heated (2)

Alcohol(1st and 2nd) oxidising agents:

  • Hot copper(Il) oxide, black to brown.

  • Acidified potassium dichromate (VI), orange to green.

Aldehyde oxidising agent (test for aldehyde):

  • Fehling's solution, blue to a brick red precipitate

  • Tollens' reagent, clear colourless to a silver mirror

Oxidising agent (redox titration):

Potassium permanganate, purple to colourless (self indicating)

Definition of bonds and forces

Open ended Questions:

  • topic(s) involved

  • Definitions/Key phrases

  • Balanced equations

  • Diagrams

  • Examples

  • Answer the question

Explain the difference between bond enthalpy and mean bond enthalpy.

Mean bond enthalpy must refer to an average energy and to a number of compounds and bond enthalpy must relate to one compound/diatomic molecule.

Supporting documents: