S asked in Science & MathematicsChemistry · 1 decade ago

How to test if a substance is sugar?

How do you test a substance to see if it is sugar, besides seeing if it dissolves in water?

Update:

How do you test a substance to see if it is sugar, besides seeing if it dissolves in water? i have really basic materials to work with (its for a chemistry class in high school)

the only liquids we are provided with are iodine, vinegar, and water.

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  • 1 decade ago
    Favorite Answer

    You can look at the crystal shapes under a microscope. For example, (if I recall correctly) you know it is salt if the shape of the crystal is a cube whereas a sugar is like a parallelogram (I think....). I know the salt and sugar crystals are different due to different chemical compounds. [Note: If your sugar is already dissolved in a liquid solution, then you can just heat the water to make it evaporate and examine the crystals left behind]

    You can also do a sugar test in Benedict's solution - Benedict's solution is clear blue solution and if you add in sugar to dissolve, the blue solution will change color to either green, yellow, or red - depending on the sugar - when you heat it gently:

    See here for more information regarding the Benedict's solution test- http://www.scribd.com/doc/3371524/Food-Chemistry-T...

    http://www.accessexcellence.org/AE/AEC/AEF/1994/je...

    That's all I can think of right now. I took honors chemistry back in high school a few years ago.

    EDIT: In regards to your additional information, there will be no reaction if you add sugar to iodine. Iodine is usually used to test for the presence of statch so in the case of starch, there would be a reaction whereas sugar would have none. If you had Benedict's solution (which you don't), starch would not have a reaction whereas sugar would.

    For the use of vinegar, if you added sugar, I would assume that sugar would dissolve but there would be no reaction. (Take for example when you cook and you add sugar to vinegar - that is how you make sweet and sour sauce - the sugar just dissolves.) However, if you let the vinegar evaporate, it would just leave you with your sugar crystals.

    I hope that gives you a bit more help?

  • 4 years ago

    1

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  • kifer
    Lv 4
    4 years ago

    Upon heating in a attempt tube the sugar will char somewhat to yield black carbon The salt won't char upon heating and in case you splatter a splash salt over a bunsen burner flame, the flame will tutor a superb yellow coloration brought about by way of the sodium steel interior the salt additionally including a splash salt to water, then dip your stirring rod interior the salt answer and carry the moist end of the rod over your burner will additionally provide you a superb yellow flame, that's the flame attempt for sodium and table salt has the formulation NaCl, sodium chloride.

  • Anonymous
    1 decade ago

    lol, you're in ms. black's chem class, right? i'm in your class...

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