Interdice
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Question 21. Would I get full marks?
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Can I just say "chemical going in eye' for every risk question (1 Viewer)
- Thread starter Interdice
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Question 21. Would I get full marks?
To your question opening the thread: You can, but it would be unwise... it is much better to tailor your response to the situation and the specific chemicals involved.
In this question, the question is:
So, the 2 marks will require a safety concern that relates to organic liquids and a strategy tied specifically to this safety concern. Since the question is addressed to "organic liquids", noting that the H+ / MnO4- used in part (b) is both strongly oxidising and corrosive would be a safety concern in the experiment being described, but it is not one relating to the organic liquids listed in part (a).
In tis case, your answer about chemicals being hazardous to eyes is true, there is a risk of this happening, and safety glasses are a suitable way to reduce the risk / address the safety concern... so yes, I think this can be a 2 / 2 answer.
In a larger question that goes to risk and safety precautions, evaluating specific concerns with tailored precautions are going to be more important than generic concerns and precautions. Wearing safety glasses to protect your eyes is a precaution that is standard for any chemistry laboratory activity and so has little (if anything) to do with the specific hazards and risks in a nominated activity. Consequently, including it in an evaluation or assessment of risk of a named activity is not adding much, though it is not wrong.
Note also that "hazard" and "risk" are not synonyms. There are plenty of circumstances where nothing can be done about a hazard but plenty can be done about risk.
In this question, the question is:
State ONE safety concern associated with organic liquids and suggest ONE way to address this safety concern.
So, the 2 marks will require a safety concern that relates to organic liquids and a strategy tied specifically to this safety concern. Since the question is addressed to "organic liquids", noting that the H+ / MnO4- used in part (b) is both strongly oxidising and corrosive would be a safety concern in the experiment being described, but it is not one relating to the organic liquids listed in part (a).
In tis case, your answer about chemicals being hazardous to eyes is true, there is a risk of this happening, and safety glasses are a suitable way to reduce the risk / address the safety concern... so yes, I think this can be a 2 / 2 answer.
In a larger question that goes to risk and safety precautions, evaluating specific concerns with tailored precautions are going to be more important than generic concerns and precautions. Wearing safety glasses to protect your eyes is a precaution that is standard for any chemistry laboratory activity and so has little (if anything) to do with the specific hazards and risks in a nominated activity. Consequently, including it in an evaluation or assessment of risk of a named activity is not adding much, though it is not wrong.
Note also that "hazard" and "risk" are not synonyms. There are plenty of circumstances where nothing can be done about a hazard but plenty can be done about risk.
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In this kind of question maybe you will get away with it but there are specific kinds of questions where they specify 'other than personal protective equipment, identify one risk associated with the experiment and how it can be minimised'. If you write going into the eyes there you won't get marks.
Also, there are specific experiments such as esterification, titration and molar heat of combustion which commonly come up in longer response questions where for 5-8 marks they might ask you to describe a full method for the experiment, how you would perform it safely and to describe how to do any associated calculations. If I was marking that and your safety precautions were just to wear lab coat and safety glasses, I wouldn't give the full marks for that component of the long response answer. That is because these 3 experiments have specific risks that are to do with that experiment only and so a better answer would specifically talk about these and talk about multiple risks instead of one general one.
To give a general idea of what that would be for esterification:
- flammable reactants and products --> need to use a hot plate, water or sand bath to heat the reaction as using a bunsen burner may lead to a fire
- concentrated sulfuric acid is used as catalyst --> highly corrosive to skin, eyes and metals so must be handled using double gloves and bottle kept closed when not in use to prevent spills. Neutralising agent such as NaHCO3 should be kept in stock in case of spill on floor or bench.
- open top of condenser --> heating up a solvent to high temperatures will lead to gas formation so if you close the top there is a chance of pressure build up and explosion
You can tie lab coat and safety glasses into the second point but as the above commenter said this is just a general precaution used in all chemistry experiments so you are better off giving something more specific.
Also, there are specific experiments such as esterification, titration and molar heat of combustion which commonly come up in longer response questions where for 5-8 marks they might ask you to describe a full method for the experiment, how you would perform it safely and to describe how to do any associated calculations. If I was marking that and your safety precautions were just to wear lab coat and safety glasses, I wouldn't give the full marks for that component of the long response answer. That is because these 3 experiments have specific risks that are to do with that experiment only and so a better answer would specifically talk about these and talk about multiple risks instead of one general one.
To give a general idea of what that would be for esterification:
- flammable reactants and products --> need to use a hot plate, water or sand bath to heat the reaction as using a bunsen burner may lead to a fire
- concentrated sulfuric acid is used as catalyst --> highly corrosive to skin, eyes and metals so must be handled using double gloves and bottle kept closed when not in use to prevent spills. Neutralising agent such as NaHCO3 should be kept in stock in case of spill on floor or bench.
- open top of condenser --> heating up a solvent to high temperatures will lead to gas formation so if you close the top there is a chance of pressure build up and explosion
You can tie lab coat and safety glasses into the second point but as the above commenter said this is just a general precaution used in all chemistry experiments so you are better off giving something more specific.