Solution Molecule

This is my drawing of a glucose molecule being hydrated by H20 molecules.

Candy Lab: Post 1

     The purpose of the is lab is to learn about the solubility and crystallization of sugar in water while also learning the process of candy making and applying chemistry to this process. The terms solution, solute, solvent, solubility, crystallization, concentration, and molarity will be important to know for this lab

     Before making candy you first have to know a thing or two about candy itself. Hard candy is made by heating sugar to at least 160 degrees Celsius, adding flavoring, and letting cool to a hard, solid candy form. Then you must learn a few important terms you will be working with in this lab. Solubility is the ability for a solute to dissolve in a solvent. An example of this could be salt (NaCl) dissolving in water (H20). Solubility (you may know it better as dissolving,) is important in candy making so that the flavor or coloring is even throughout all the candy. Crystallization happens when solid crystals form from a liquid and are deposited by a gas. Snowflakes are an easy example of this. If you look at a snow flake you an see tiny feathery ice crystals are frozen together, giving it its flake-ish shape. Concentration is the amount of a substance per defined space. For example, when you put a drop of dye in some water, you can see the water turn a pale shade of that color. But if you put several drops of dye in the same amount of water, you can see a the water turn a more vivid shade of color. Another thing to know about is a solubility curve. As stated by www.saskschool.ca, a solubility curve is "a graph showing the relationship between solubility and temperature." Here is an example of a solubility curve published by http://scienceprojectideasforkids.com/2010/what-is-a-supersaturated-solution/. When looking at this graph you can figure out the relationship between sugar and temperature. When I went on this website, http://www.kentchemistry.com/links/Kinetics/SolubilityCurves.htm, I learned the different relationships to explain the graph above. The black line labeled "sugar" is the point at which the solvent is saturated (the water cannot dissolve anymore solute). That means that when the negative end of a sugar bonds with the positive end of a water molecule, the water molecules will take the sugar molecule away from the sugar crystal. When all the water molecules have bonded with all the sugar molecules, the solvent becomes saturated. Anything above the line is supersaturated (there is too much sugar for the water to dissolve and its just clumping to itself) and anything below is unsaturated (more sugar is able to dissolve). In 100g of water at zero degrees Celsius about 175g of sugar are able to dissolve in the solvent and at 80 degrees Celsius about 360g of sugar are able to be dissolved. Basically, the higher the temperature the more solvent the solute is able to dissolve.

     You will now demonstrate your knowledge of these terms by following a simple candy recipe and producing a batch of hard candy. You will be able to evaluate your work by the outcome of your candy. When finished you will know if you did well if your hard candy ends up hard, the color and flavor is even and consistent, and if the candy looks like candy.

Candy Lab: Post 2



1. Edited recipe retrieved on 12/9/13 and cited from: http://lorannoils.com/node/73

   Hard Candy Recipe

   Safety

     -HOT sugar is dangerous to come in contact with. Do NOT touch!
     -Heating implement in use. Use with CAUTION!
     -Wear lab appropriate safety clothing: goggles, aprons, gloves, hair tied back, no loose garments

   Ingredients

    -2 cups granulated sugar

    -2/3 cup light corn syrup

    -¾ cup water

    -1 tsp flavoring

    -liquid food coloring

   
   
    -large coffee can
    -bunson burner
    -stirring spoon
    -candy thermometer
    -cookie sheet
    -pastry brush

   ——

   Use of a candy thermometer is recommended

   Directions

     1.  In a large coffee can, mix together sugar, corn syrup and water. Stir over medium heat until sugar dissolves.
     2.  Insert candy thermometer, making certain it does not touch the bottom of the can. Bring mixture to a boil without stirring.
     3.  While cooking down the sugar mixture, scrape any sugar crystals that form on the sides of the pan with a wet pastry brush back into the main solution.  
     4.  Continue to cook, without stirring, until the temperature reaches 260º F; add drops of coloring until desired hue is achieved. Do not stir (boiling will incorporate color into syrup).
     5.  Remove from heat precisely at 300° F, or until drops of syrup form hard, brittle threads in cold water (hard crack stage). After boiling action has ceased, add flavor and stir. USE CAUTION WHEN ADDING FLAVORING TO AVOID RISING STEAM.
     6.  Carefully pour syrup onto a cookie sheet and spread out into a thin sheet before cooling.
     7.  Cool completely. Break sheet candy into small pieces. Store in airtight containers between waxed paper. Store hard candy in a cool, dry place. Do not refrigerate.