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dumNerd

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For chem mod 1 and just the sciences in general, when describing a method are we allowed to write in number points or does it have to be a paragraph. Eg. My current question:

Jack has a mixture of flour and sugare that he must separate. However, he discovers that he cannot use a sieve to dot his. Suggest why the use of a sieve of inappropriate, and describe an alternate separation technique, identifying the properties this technique relies on.

Can I answer like this: A sieve was inappropriate as in order for it to seperate the components of a mixture, the particles of constituent components must vary by a larger margin than flour and sugar particles. Instead, she could:
1. Add water to the mixture, causing the sugar to dissolve (property relied upon is differing solubility)
2. Separate the flour from the aqueous solution through filtration (property relied upon is particle size)
3. Through evaporation, separate the water from the sugar (property relied upon is differing boiling points)

CAN I WRITE MY ANSWER EXACTLY AS I HAVE ABOVE
 

dumNerd

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For chem mod 1 and just the sciences in general, when describing a method are we allowed to write in number points or does it have to be a paragraph. Eg. My current question:

Jack has a mixture of flour and sugare that he must separate. However, he discovers that he cannot use a sieve to dot his. Suggest why the use of a sieve of inappropriate, and describe an alternate separation technique, identifying the properties this technique relies on.

Can I answer like this: A sieve was inappropriate as in order for it to seperate the components of a mixture, the particles of constituent components must vary by a larger margin than flour and sugar particles. Instead, she could:
1. Add water to the mixture, causing the sugar to dissolve (property relied upon is differing solubility)
2. Separate the flour from the aqueous solution through filtration (property relied upon is particle size)
3. Through evaporation, separate the water from the sugar (property relied upon is differing boiling points)

CAN I WRITE MY ANSWER EXACTLY AS I HAVE ABOVE
bump
 

Directrix

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I had the same type of question for prelims and got full marks by doing a method like you.

(my teacher is a hsc marker)
 

CM_Tutor

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You can't separate sugar from water by evaporation.

Further, mixing flour and water is not like mixing sand and water, you don't get a nice layer of solid sitting below a solution of sugary water. These three mix to form a dough.
 

tito981

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teachers dont care how you present info in the sciences. my teachers have said that for longer response questions even dot points are accepted. this is unless the question instructs a procedure e.g. flowchart.
 

dumNerd

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teachers dont care how you present info in the sciences. my teachers have said that for longer response questions even dot points are accepted. this is unless the question instructs a procedure e.g. flowchart.
So it's fine as long as you have what they want down on the paper?
 

dumNerd

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You can't separate sugar from water by evaporation.

Further, mixing flour and water is not like mixing sand and water, you don't get a nice layer of solid sitting below a solution of sugary water. These three mix to form a dough.
" You can't separate sugar from water by evaporation. " Why not
 

CM_Tutor

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" You can't separate sugar from water by evaporation. " Why not
In all seriousness, I suggest that you ask your mother - or whoever does most of the cooking where you live.

There are many things that can be cooked using sugar and water.
 

Qeru

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" You can't separate sugar from water by evaporation. " Why not
google how caramel is made, but generally I think for the HSC atleast evaporation should be fine.
 

Eagle Mum

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" You can't separate sugar from water by evaporation. " Why not
You can separate sugar & water by distillation which involves evaporation then condensation of the water.
There are YouTube videos with demonstrations.

A previous poster was correct to advise that it will turn into caramel if the temperature is too hot. Water boils at 100 deg C and sugar caramelises at 320 deg C, so a temperature between 100-150 deg C should work.
 
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dumNerd

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In all seriousness, I suggest that you ask your mother - or whoever does most of the cooking where you live.

There are many things that can be cooked using sugar and water.
As you evaporate it wouldn't the water become too concentrated, and so it wouldn't be able to hold all the sugar particles and so the sugar particles would crystallise
You can separate sugar & water by distillation which involves evaporation then condensation of the water.
Here’s a YouTube video of a demonstration in real time.

A previous poster was correct to advise that it will turn into caramel if the temperature is too hot. Water boils at 100 deg C and sugar caramelises at 320 deg C, so a temperature between 100 -150 deg C should work.
thanks, but I don't need the water so is there any reason to condense it again?
 

Eagle Mum

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As you evaporate it wouldn't the water become too concentrated, and so it wouldn't be able to hold all the sugar particles and so the sugar particles would crystallise

thanks, but I don't need the water so is there any reason to condense it again?
Yes, crystallisation of the sugar does separate it from the water so it is the intention of the exercise.
If you don’t need the water, condensation is unnecessary. (Sorry, I’ve only just read the original post - I was replying to your post later in the thread.)
 
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dumNerd

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Yes, crystallisation of the sugar does separate it from the water so it is the intention of the exercise.
If you don’t need the water, condensation is unnecessary. (Sorry, I’ve only just read the original post - I was replying to your post later in the thread.)
All good thanks for all the help!!!! Also I don't understand why exactly the sugar crystallize. Based on what I know it crystallizes because the solution becomes too concentrated as the amount of sugar remains constant but the liquid decreases and so it binda with others sugar particles and crystallizes? The websites don't really specify
 

Eagle Mum

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All good thanks for all the help!!!! Also I don't understand why exactly the sugar crystallize. Based on what I know it crystallizes because the solution becomes too concentrated as the amount of sugar remains constant but the liquid decreases and so it binda with others sugar particles and crystallizes? The websites don't really specify
Sucrose (common table sugar which is a disaccharide of glucose and fructose) is a weakly polar molecule (even though it is not ionic), so sucrose molecules are attracted to each other and held together by intermolecular forces.
 

dumNerd

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Sucrose (common table sugar which is a disaccharide of glucose and fructose) is a weakly polar molecule (even though it is not ionic), so sucrose molecules are attracted to each other and held together by intermolecular forces.
but why do they attract to each other? Is it because of the reason I stated?
 

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ezOolong

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Underlines for emphases, bulleted lists for any info, subheadings for each section, even comparison tables, etc, are PERFECT for answering long response questions in science. I strongly recommend using these to make your information clear (as I am a messy writer ;3)

For shorter questions, you can decide if you want to use these or not.
 

dumNerd

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Underlines for emphases, bulleted lists for any info, subheadings for each section, even comparison tables, etc, are PERFECT for answering long response questions in science. I strongly recommend using these to make your information clear (as I am a messy writer ;3)

For shorter questions, you can decide if you want to use these or not.
O really? I thought all of this stuff wasn't allowed. I'v never seen someone use dotpoints or anything and yes I'm also terrible and conveying what I want to in long sentences so this would be a life saver
 

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