Turn on thread page Beta
    • Thread Starter
    Offline

    0
    ReputationRep:
    1(a)(i) fizz / effervescence / bubbles
    because carbon dioxide
    produced / released
    limewater turns cloudy / milky /
    white
    because (a precipitate of or
    solid) calcium carbonate forms
    allow calcium carbonate
    decreases in size or
    dissolves
    allow because gas
    produced / released
    allow because of carbon
    dioxide if not already
    credited
    1
    1
    1
    1
    AO2/AO3
    3.4.1d,
    3.6.2b
    1(a)(ii) allow –OH
    do not allow lower case ‘h’
    1 AO1
    3.6.2a
    1(a)(iii) acid
    ester(s)
    must be in this order
    ignore any name of an acid
    1
    1
    AO1
    3.6.2b
    1(b)
    white (precipitate) no change
    no change no change
    all four correct 2 marks
    any two correct 1 mark
    2
    AO2
    3.4.1e,f
    1(c)(i)
    lilac
    red
    must be in this order
    allow purple 1
    1
    AO1
    3.4.1a
    1(c)(ii) colours are masked / changed
    by each flame colour
    1 AO3
    3.4.1a
    Total 12
    MARK SCHEME – GCSE CHEMISTRY – CH3HP – JUNE 2016
    7 of 11
    Question Answers Extra information Mark AO /
    SpecRef
    2 6 2AO1 /
    3AO2 /
    1AO3
    3.4.1g
    Marks awarded for this answer will be determined by the Quality of Written
    Communication (QWC) as well as the standard of the scientific response. Examiners
    should also refer to the information on page 5 and apply a ‘best-fit’ approach to the
    marking.
    0 marks Level 1 (1–2 marks) Level 2 (3–4 marks) Level 3 (5–6 marks)
    No relevant
    content.
    There is a simple
    description of using
    some of the
    apparatus.
    There is a
    description of an
    experimental method
    including addition of
    acid to alkali which
    may include an
    indicator or colour
    change and may
    include a
    measurement of
    volume.
    There is a
    description of
    titrations that would
    allow a comparison
    to be made between
    the two solutions of
    hydrochloric acid.
    examples of chemistry points made in the response could include:
    • acid in burette or flask
    • alkali/sodium hydroxide or acid in burette or flask
    • volume of acid or alkali measured using the pipette
    • indicator in flask
    • white tile under the flask
    • slow addition
    • swirling/mixing
    • colour change of indicator
    • burette volume measured
    Total 6
    MARK SCHEME – GCSE CHEMISTRY – CH3HP – JUNE 2016
    8 of 11
    Question Answers Extra information Mark AO /
    SpecRef
    3(a)(i) atomic weights allow atomic masses 1 AO1
    3.1.1a
    3(a)(ii) proton allow proton number 1 AO1
    3.1.2a
    3(b)(i) F/fluorine allow F2 1 AO3
    3.1.3a,b,f
    3(b)(ii)
    any one from:
    • copper has a higher density
    • copper is stronger
    • copper is harder
    • copper is less reactive
    allow converse for
    potassium
    allow named property
    ignore colour, conductivity,
    melting point and boiling
    point
    1
    AO1
    3.1.3c
    3(b)(iii)
    relative distance from nucleus
    relative attraction to nucleus
    relative ease of gain or loss of
    electron
    opposite explanation of ease of
    gain or loss of electron for other
    group
    max 3 marks if ‘outer’ not
    mentioned
    allow more / fewer energy
    levels / shells or larger /
    smaller atom
    allow more / less shielding
    1
    1
    1
    1
    2AO1 /
    1AO2 /
    1AO3
    3.1.3b,f,h
    Total 8
    MARK SCHEME – GCSE CHEMISTRY – CH3HP – JUNE 2016
    9 of 11
    Question Answers Extra information Mark AO /
    SpecRef
    4(a) development / maintenance of
    teeth / bones
    because contains
    calcium ions / compounds
    allow lowers risk of heart
    disease
    allow contains calcium
    1
    1
    AO1
    3.2.1f
    4(b) scum or calcium stearate 1 AO1
    3.2.1a
    4(c) temporary hard water contains
    calcium hydrogencarbonate or
    hydrogencarbonate ions
    when heated / boiled these
    decompose
    to produce a precipitate / scale
    or to produce calcium
    carbonate
    coats the heating element or
    coats the kettle
    allow hydrogencarbonate
    allow decompose (in the
    kettle)
    allow prevents heat /
    energy transfer to the
    water
    1
    1
    1
    1
    1AO1 /
    2AO2 /
    1AO3
    3.2.1c,d,e
    4(d)
    ion exchange resins contain
    sodium / hydrogen ions
    which replace / remove the
    calcium / magnesium ions
    so removing the hardness or
    producing soft water
    ions must be mentioned
    once to gain both of the
    first two marking points
    allow displace, but do not
    allow references to
    reactivity series
    1
    1
    1
    2AO1 /
    1AO2
    3.2.1g,
    3.2.2b
    Total 10
    MARK SCHEME – GCSE CHEMISTRY – CH3HP – JUNE 2016
    10 of 11
    Question Answers Extra information Mark AO /
    SpecRef
    5(a) CH4 + 2O2 
    CO2 + 2H2O
    allow multiples 1 AO2
    3.3.1a
    5(b) 3444 J
    if answer incorrect:
    one mark for temperature
    increase = 16.4 °
    C
    one mark for mass of water
    = 50 g
    ecf for one incorrect value
    gains two marks for correct
    calculation
    no ecf for two incorrect
    values
    3 AO2
    3.3.1a
    5(c)(i) 1276 (kJ per mole) ignore + or -
    if answer incorrect:
    [(5 x 413) + 347 + 358 +467]
    + [(3 x 495)] = 4722 (1 mark)
    [(4 x 799) + (6 x 467)] =
    5998 (1 mark)
    correct subtraction of
    calculated energy values (1
    mark)
    3 AO2
    3.3.1f
    5(c)(ii) because energy released
    when bonds form is greater
    than energy used when bonds
    broken
    allow converse
    if no mark awarded allow
    one mark for energy is used
    to break bonds
    or
    one mark for energy is
    released when bonds form
    2 AO1
    3.3.1e,f
    5(c)(iii) products line lower than
    reactants
    activation energy labelled
    overall energy change labelled
    1
    1
    1
    2AO2 /
    1AO3
    3.3.1d
    Total 12
    MARK SCHEME – GCSE CHEMISTRY – CH3HP – JUNE 2016
    11 of 11
    Question Answers Extra information Mark AO /
    SpecRef
    6(a)(i) natural gas allow fossil fuels / biogas
    generator
    1 AO1
    3.5.1a
    6(a)(ii) air contains oxygen
    this would react with / oxidise
    the hydrogen
    allow this would react with
    / oxidise the iron
    ignore nitrogen
    1
    1
    AO3
    3.5.1b
    6(a)(iii) cooled
    ammonia condenses / liquefies
    (so can be separated)
    nitrogen and hydrogen (remain
    as gases and) are returned to
    the reactor
    allow recycled
    1
    1
    1
    AO1
    3.5.1b
    6(b)(i) 200 °C and 1000 atmospheres 1 AO3
    3.5.1b
    6(b)(ii) the reaction is reversible
    forward reaction is exothermic
    so increased temperature
    lowers the yield of ammonia
    a lower temperature would
    decrease rate of reaction
    a higher pressure would
    increase the yield of ammonia
    because the forward reaction
    produces the least number of
    (gaseous) molecules / moles
    higher pressures would involve
    high cost / energy
    allow stated as equilibrium
    or forward / backward
    reaction anywhere in
    answer
    allow converse
    allow converse
    allow converse
    ignore risk / explosion
 
 
 

University open days

  1. University of Bradford
    University-wide Postgraduate
    Wed, 25 Jul '18
  2. University of Buckingham
    Psychology Taster Tutorial Undergraduate
    Wed, 25 Jul '18
  3. Bournemouth University
    Clearing Campus Visit Undergraduate
    Wed, 1 Aug '18
Poll
How are you feeling in the run-up to Results Day 2018?
Useful resources

Study tools

Rosette

Essay expert

Learn to write like a pro with our ultimate essay guide.

Thinking about uni already?

Thinking about uni already?

See where you can apply with our uni match tool

Student chat

Ask a question

Chat to other GCSE students and get your study questions answered.

Creating

Make study resources

Create all the resources you need to get the grades.

Planner

Create your own Study Plan

Organise all your homework and exams so you never miss another deadline.

Resources by subject

From flashcards to mind maps; there's everything you need for all of your GCSE subjects.

Papers

Find past papers

100s of GCSE past papers for all your subjects at your fingertips.

Help out other students

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.