Title: Identification of Wool
Objective: The objective of this lab is to identify wool using its physical and chemical properties.
Materials:
- Wool sample
- Microscope
- Beaker
- Water
- Sodium hydroxide
- Hydrochloric acid
- Acetic acid
- Ammonia
- Petri dish
- Glass slides
- Cover slips
- Forceps
Procedure:
- Visual examination: a) Examine the wool sample with the naked eye and note its color, texture, and other physical characteristics.
b) Under a microscope, examine the wool fibers and note the size, shape, and color of the fibers. Wool fibers should have scales on them that give them a unique look under the microscope.
- Chemical tests: a) Take a small piece of wool and put it into a beaker of water. Gently stir the water and wool with a glass rod. Note the behavior of wool in water. Wool is known to be hydrophilic, so it should absorb water.
b) Take another small piece of wool and put it into a beaker of sodium hydroxide solution. Observe the reaction of the wool with the sodium hydroxide. Wool should dissolve in sodium hydroxide.
c) Take another small piece of wool and put it into a beaker of hydrochloric acid. Observe the reaction of the wool with the acid. Wool is known to be resistant to acid, so it should not dissolve.
d) Take a small piece of wool and place it on a Petri dish. Add a few drops of acetic acid to the wool. Note the reaction of the wool with acetic acid. Wool should dissolve in acetic acid.
e) Take a small piece of wool and place it on a Petri dish. Add a few drops of ammonia to the wool. Note the reaction of the wool with ammonia. Wool should turn dark brown in the presence of ammonia.
- Microscopic examination: a) Take a small amount of wool fibers and place them on a glass slide.
b) Cover the fibers with a cover slip and examine under a microscope.
c) Note the size, shape, and structure of the fibers.
d) Note the presence of any contaminants or other materials in the wool fibers.
Conclusion: Based on the visual, physical, and chemical properties observed during the experiment, it can be concluded whether or not the sample is wool. If the sample exhibits all of the properties of wool, including its characteristic physical appearance, hydrophilic nature, and reaction with chemicals such as sodium hydroxide, acetic acid, and ammonia, then it can be identified as wool. If the sample does not exhibit these properties, then it is likely not wool.