Easy Notes

Table 6.1
Solutions and Color Reactions for “Benedict’s Test for Reducing Sugars” and “Iodine Test for Starch.” Solution | Benedict’s Color Reaction | Iodine Color Reaction | 10 drops onion juice | Brownish orange, an abundance of reducing sugars. | Yellow and White (-) | 10 drops potato juice | Greenish yellow, a small amount of reducing sugars. | Yellowish brown and White (-) | 1% sucrose solution | Blue, non-reducing sugars. | Yellow. (-) | 1% glucose solution | Dark orange, an abundance of reducing sugars. | Yellow. (-) | 10 drops distilled water | Blue, non-reducing sugars. | Yellow. (-) | 10 drops reducing-sugar solution | Reddish orange, an abundance of reducing sugars. | Yellow. (-) | 1% starch solution | Blue, non-reducing sugars. | Dark blue. (+) | 10 drops honey solution | Bright orange, an abundance of reducing sugars. | Yellow and clear. (-) | Unknown #4 | Reddish orange, an abundance of reducing sugars. | Yellow. (-) |

Table 6.2
Solutions and Color Reactions for the Biuret Test for Protein Solution | Color | 2 mL egg albumen | Dark violet (+) | 2 mL honey | Yellow (-) | 2 mL amino acid solution | Pale blue (weak +) | 2 mL distilled water | Pale blue (weak +) | 2 mL protein solution | Violet (+) | Unknown #4 | Pale blue (weak +) |

Procedure 6.4
When we added a few drops of vegetable oil to 5mL of water, the oil separated from the water, meaning it is insoluble in polar solvents. When we added a few drops of vegetable oil to 5mL of acetone, the oil mixed in with the acetone, meaning it is soluble with nonpolar solvents.
Table 6.3
Solutions and Color Reactions for the Sudan IV Test for Lipids Solution | Description of Reaction | 1 mL vegetable oil + water | Oil separated from the water, (+) for lipids | 1 mL vegetable oil + Sudan IV | Separated and did not mix well, (+) for lipids | 1 mL honey + Sudan IV | Mixed well, (-) for lipids | 1 mL distilled water + Sudan IV | Mixed well, (-) for