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    hi everyone how are you??
    i need to ask you guys some question
    firstly, for a 1 mark question when they ask describe an observation that you would see when you heat ammonium chloride- can you say the solid disappers and you can see the vapour coming out of the test tube to the cooler part? can that get you 1 mark?

    Also, is it true when you add calcium chloride to Nacl you see no reaction but it said give one observation and i said there were little bits of crystals formed howver the answer is no reaction do you think my answer could also be a possibility?

    Also, guys if they said give an observation when adding magnesium ribbon to sulphuric acid do you write vigorous fizzing and the test tube gets cooler for 1 mark and is it necessary to write down the reason such as saying faster rate of reaction? for the obervation?

    thanks guys
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    i would use effervescence if i were you
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    (Original post by kimmey)
    i would use effervescence if i were you
    how about the others because fizzing means same thing i put
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    Never fizzing. Always effervescence. It doesn't matter whether they mean the same thing, always put down effervescence.
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    (Original post by Accalia)
    Never fizzing. Always effervescence. It doesn't matter whether they mean the same thing, always put down effervescence.
    how about the rest ?? are they fine ?
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    (Original post by otrivine)
    hi everyone how are you??
    i need to ask you guys some question
    firstly, for a 1 mark question when they ask describe an observation that you would see when you heat ammonium chloride- can you say the solid disappers and you can see the vapour coming out of the test tube to the cooler part? can that get you 1 mark?

    Also, is it true when you add calcium chloride to Nacl you see no reaction but it said give one observation and i said there were little bits of crystals formed howver the answer is no reaction do you think my answer could also be a possibility?

    Also, guys if they said give an observation when adding magnesium ribbon to sulphuric acid do you write vigorous fizzing and the test tube gets cooler for 1 mark and is it necessary to write down the reason such as saying faster rate of reaction? for the obervation?

    thanks guys
    I think we're on separate exam boards, because I've not encountered those reactions before. So, assuming that you're observations were right (it's always good to check online, because some chemicals which you add in the lab that shouldn't react can do because of impurities).

    Heating ammonium chloride - I'd say it thermally decomposes from a salt into a liquid (ammonia) and a gas, as fumes are given off.

    Calcium chloride + NaCl - if there's no reaction (pretty believable), you can still make the observation that the liquids/salts haven't changed. There are no obvious signs of anything happening. Those crystals you saw may just be due to the temperature you mixed the chemicals at.

    Magnesium ribbon + sulphuric acid - like I said, mention that the mixture effervesces and as for the test tube getting cooler, perhaps drop the word endothermic?

    Ultimately, the best way to answer these questions will be on the mark scheme. You understand what they're asking for, you just need to use a few more scientific terms.
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    (Original post by Accalia)
    I think we're on separate exam boards, because I've not encountered those reactions before. So, assuming that you're observations were right (it's always good to check online, because some chemicals which you add in the lab that shouldn't react can do because of impurities).

    Heating ammonium chloride - I'd say it thermally decomposes from a salt into a liquid (ammonia) and a gas, as fumes are given off.

    Calcium chloride + NaCl - if there's no reaction (pretty believable), you can still make the observation that the liquids/salts haven't changed. There are no obvious signs of anything happening. Those crystals you saw may just be due to the temperature you mixed the chemicals at.

    Magnesium ribbon + sulphuric acid - like I said, mention that the mixture effervesces and as for the test tube getting cooler, perhaps drop the word endothermic?

    Ultimately, the best way to answer these questions will be on the mark scheme.

    You understand what they're asking for, you just need to use a few more scientific terms.
    mine is OCR cause you see i added the Mg ribbon to Nacl i know there is no reaction but i am sure i saw 10 crystals floaing around the test tube and when they say observe i mean you have to write what you see. or do you think cause the test tube was not clean enough i saw these crystals? but are my correct for the ammonium chloride and sadly i cant find the mark scheme?
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    (Original post by otrivine)
    hi everyone how are you??
    i need to ask you guys some question
    firstly, for a 1 mark question when they ask describe an observation that you would see when you heat ammonium chloride- can you say the solid disappers and you can see the vapour coming out of the test tube to the cooler part? can that get you 1 mark?

    Also, is it true when you add calcium chloride to Nacl you see no reaction but it said give one observation and i said there were little bits of crystals formed howver the answer is no reaction do you think my answer could also be a possibility?

    Also, guys if they said give an observation when adding magnesium ribbon to sulphuric acid do you write vigorous fizzing and the test tube gets cooler for 1 mark and is it necessary to write down the reason such as saying faster rate of reaction? for the obervation?

    thanks guys
    If you've done the practical, you shouldn't be discussing it and if you haven't, that's even worse to post it up on here. So either way, this topic shouldn't exist. These things are supposed to be discussed with your teachers, they should atleast give you a guideline, also go to the OCR website and see the specimen papers - they give you a good outline of how to answer.
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    (Original post by LifeIsGood)
    If you've done the practical, you shouldn't be discussing it and if you haven't, that's even worse to post it up on here. So either way, this topic shouldn't exist. These things are supposed to be discussed with your teachers, they should atleast give you a guideline, also go to the OCR website and see the specimen papers - they give you a good outline of how to answer.
    this is not practical its just the questions in my text book thats why i am going over it?
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    (Original post by otrivine)
    hi everyone how are you??
    i need to ask you guys some question
    firstly, for a 1 mark question when they ask describe an observation that you would see when you heat ammonium chloride- can you say the solid disappers and you can see the vapour coming out of the test tube to the cooler part? can that get you 1 mark?

    Also, is it true when you add calcium chloride to Nacl you see no reaction but it said give one observation and i said there were little bits of crystals formed howver the answer is no reaction do you think my answer could also be a possibility?

    Also, guys if they said give an observation when adding magnesium ribbon to sulphuric acid do you write vigorous fizzing and the test tube gets cooler for 1 mark and is it necessary to write down the reason such as saying faster rate of reaction? for the obervation?

    thanks guys
    1) Never say solid disappears, say solid dissolves.
    2) Yes there will be no reaction between sodium chloride and calcium chloride, both of these substances are aqueous in solution, so it is unlikely that crystals will form unless it's a saturated solution.
    3) Observation = fizzing that's all you'll need.
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    Usually answers to these questions require only one or two 'key words' for example, effervescence or white precipitate formed, lilac flame, sinks and rises, dissolves.
    Sorry, I'm unfamiliar with your reactions.
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    (Original post by Cambridge_lad)
    1) Never say solid disappears, say solid dissolves.
    2) Yes there will be no reaction between sodium chloride and calcium chloride, both of these substances are aqueous in solution, so it is unlikely that crystals will form unless it's a saturated solution.
    3) Observation = fizzing that's all you'll need.
    but when you heat it i am sure saying disappear is better than saying dissolve cause dissolve is if u put it in water and it goes? and the reaction between Cacl2 and Nacl there is no reaction but then why did i see some crystals forming? i put only little bit if crystals are formed ?
    and when you heat the ammnoim choride i did put that the vapor comes out of the test tube to the cooler part?
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    (Original post by MJ*)
    Usually answers to these questions require only one or two 'key words' for example, effervescence or white precipitate formed, lilac flame, sinks and rises, dissolves.
    Sorry, I'm unfamiliar with your reactions.
    but when you heat it i am sure saying disappear is better than saying dissolve cause dissolve is if u put it in water and it goes? and the reaction between Cacl2 and Nacl there is no reaction but then why did i see some crystals forming? i put only little bit if crystals are formed ?
    and when you heat the ammnoim choride i did put that the vapor comes out of the test tube to the cooler part?
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    (Original post by otrivine)
    but when you heat it i am sure saying disappear is better than saying dissolve cause dissolve is if u put it in water and it goes? and the reaction between Cacl2 and Nacl there is no reaction but then why did i see some crystals forming? i put only little bit if crystals are formed ?
    and when you heat the ammnoim choride i did put that the vapor comes out of the test tube to the cooler part?
    "dissappear" could be correct if that is the case, but it isn't a key scientific term - perhaps "dissolve" or "it evaporates completely" are often more accurate or relevant terms.
    If you saw crystals forming, you saw crystals forming. You can't brush it under the carpet!! If I were you I would ask your teacher if this is right. I do know that both calcium chloride and sodium chloride can exist as crystalls.
    If vapour is released in a reaction, it is more commonly described as "XXX gas evolved", unless it is water vapour, and it is normally paired with effervescence.
 
 
 

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