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    (Original post by milolj)
    Will you lose a mark for saying 1623 rather than -1623?
    I got -486 or something
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    (Original post by lilacpotato)
    Last question: Using graph, suggest and explain why 450 degrees C and 200 atmospheres are the conditions for the Haber Process (5 marks)


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    Temperature is compromise between low for higher yield as exothermic is favoured, and rate as rate is faster with higher temperature. pressure is compromise between high for favouring ammonia producing reaction, and low for safety and cheaper running.
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    (Original post by bod247)
    Its Rb because in group 1 (alkali metals), the Boiling point and Melting Point decrease as you go down. Rb was the last Alkali Metal so its the lowest Boiling Melting/Point.
    I put iodine lmao
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    (Original post by user2k16)
    the bond energy question I didn't get a minus (-) as it was an endothermic reaction ?
    It was definitely an exothermic reaction which gave a negative enthalpy change and I'm 100%on this because at the start of the next question is said "this reaction is exothermic" lol
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    (Original post by CaptErin)
    They usually put the minus in brackets on the mark scheme like '(-) 1623' so you should be fine
    You don't lose mark
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    (Original post by bod247)
    Its Rb because in group 1 (alkali metals), the Boiling point and Melting Point decrease as you go down. Rb was the last Alkali Metal so its the lowest Boiling Melting/Point.
    Yeah but fluorine was there and is a gas at room temperature whereas rubidium isnt
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    The fill in the blanks question was an acid catalyst and an eater right?
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    It's flourine because it's a gas at room temperature. Rubidium is a metal and therefore is not
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    (Original post by milolj)
    Will you lose a mark for saying 1623 rather than -1623?
    I don't think so, i was looking at a mark scheme a couple of days ago for a similar question and it had the minus written in brackets
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    (Original post by YAY GCSE)
    It was definitely an exothermic reaction which gave a negative enthalpy change and I'm 100%on this because at the start of the next question is said "this reaction is exothermic" lol
    I am sooo blind
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    (Original post by milolj)
    Will you lose a mark for saying 1623 rather than -1623?
    No
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    (Original post by TheAnon121)
    Post your answers below, and we'll get an unofficial mark scheme!

    Random answers:
    Bond energies: -1623 or -1276 - Not sure which one is right
    Explain why: Energy needed making bonds was greater than energy released breaking bonds
    Balance equation: 2 and 2 somewhere
    Efficiency of Kettle: Hydrogencarbonate ions thermally decompose to calcium ions, then react with carbon to product a precitipates of calcium carbonate (limescale). Limescale is a bad conductor of electricity - more energy needed to heat water
    Hard water cleaner q: Calcium and magnesium ions replaced by sodium and hydrogen ions
    Benefits of hard water: contains calcium which strengthens teeth and bones
    Element that has low boiling point (or something: Rb or F (not sure)
    What happens in the mixture of gases? Ammonia is liquified, then cooled - Nitrogen and Hydrogen are recycled
    Specific heat capacity: 3444J
    For bond energies I am 100% sure it should be (-)1,276. I wrote out all the bonds underneath next to their bond energies, added up each side of the reaction and checked the numbers 3 times (I finished quite early so thought I'd count up each side again)


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    (Original post by GCSEstudentt)
    I put iodine lmao
    It's flourine, rubidium is solid at room temp flourine is gas at low temp.
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    For the titration question , i said to put the alkali in the burette and acid in the flask does it make a difference?
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    How many marks was the Specific Heat Capacity question
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    (Original post by Roquebrune2014)
    For bond energies I am 100% sure it should be (-)1,276. I wrote out all the bonds underneath next to their bond energies, added up each side of the reaction and checked the numbers 3 times (I finished quite early so thought I'd count up each side again)


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    I am agree, I redo outside three time and -1276 is my answer
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    (Original post by bod247)
    Its Rb because in group 1 (alkali metals), the Boiling point and Melting Point decrease as you go down. Rb was the last Alkali Metal so its the lowest Boiling Melting/Point.
    Sorry but the answer is indeed F (thank Google)
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    (Original post by Lmemon123)
    For the titration question , i said to put the alkali in the burette and acid in the flask does it make a difference?
    Nope they accept converse, you're fine


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    (Original post by milolj)
    Will you lose a mark for saying 1623 rather than -1623?
    Not in GCSE
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    What did everyone get on that table question which asks about the changes of the solutions?
    I got white precipitate for the calcium one, no change for both the water one, no change for one of potassium and for the other potassium one I wrote fizzing and bubbling which i think is probably wrong.
 
 
 
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