A conical flask is a type of laboratory flask with a wide, flat bottom and an inverted cylindrical neck used in scientific work for transportation, storage, and mixing purposes. It is also commonly known as an Erlenmeyer flask or titration flask, or E-flask. It was first introduced by German chemist Richard August Carl Emil Erlenmeyer in 1860.
Conical flasks are mostly made of heat-resistant borosilicate glass that helps to withstand thermal stress. They are applicable in various chemistry, biology, or microbiology laboratory to conduct scientific works.
Features of Conical Flask
- Shape: Conical flask has a smooth cylindrical shape with a narrow neck and broad base.
- Precise graduation: It consists of clear and visible graduation in the neck region.
- Wide round neck opening: It allows smooth liquid pouring as well as easy cleaning.
- Heat resistant: It is mainly made of borosilicate glass which makes it heat tolerant.
- Variety of size: Conical flask is available in various sizes that allow a wide range of applications.
- High transparency: Conical flasks have a high degree of transparency because they are made of borosilicate glass.
- Ground glass stopper: Many conical flasks are available with a ground glass stopper that provides an airtight seal so that even gaseous compounds can be stored.
Types of Conical Flasks
Conical flasks are available in two varieties based on the width of the mouth;
- Narrow mouth: Because of its tiny mouth, it helps to support the funnel during the experiment.
- Wide mouth: Liquid inside it can be stirred by a rod. Similarly, the wide mouth of the conical flask also facilitates the addition of solid samples
Available sizes of Conical Flask
The conical flask is built based on ASTM (American Society for Testing and Materials) and ISO specifications (International Organization for Standardization). They are available in various sizes including; 25 ml, 50 ml, 100 ml, 125 ml, 150 ml, 250 ml, 300 ml, 500 ml, 1000 ml, 2000 ml, 3000 ml, 4000 ml, 5000 ml, and 6000 ml.
Applications of the Conical Flask
Conical flask has a wide range of applications in the chemistry, biology, and microbiology fields for heating, mixing, and transferring chemicals or reagents;
- In chemistry: Erlenmeyer flasks are used for various purposes in a chemistry laboratory. Because of its irregular shape, it is best for swirling liquid. As a result, it is used in titration experiments. Similarly, conical flasks are also used to boil liquids. The top of the Erlenmeyer flask helps to condense the solvent. The narrow neck and reducing solvent loss can also enhance the capability of recrystallization.
- In biology: In biology, conical flasks are used to produce microbial culture needed during tissue culture or DNA extraction.
- In microbiology: In the microbiology laboratory, conical flasks are also used to boil and sterilize culture media while preparing the culture plates.
Advantages of Conical Flask
Conical flasks are an important laboratory glassware that has the following advantages;
- The conical flasks can be used for various purposes like mixing, heating, and storing chemicals or reagents.
- Conical flasks are usually heat resistant in nature. Therefore, it is used to heat chemicals or reagents.
- The flaring neck of the conical flask helps to pour liquid easily.
- Its design of having a broad base with a narrow neck helps in stirring or rotating liquid without spillage.
- The small neck of the conical flask reduces evaporation loss during heating.
Disadvantages of Conical Flask
Conical flasks do have some drawbacks despite their benefits, such as;
- It is not used for measurement purposes because of its irregular shape.
- It has a limited thickness, due to which it cannot be used for high chemical reactions.
- It can be easily cracked or damaged by improper handling.
Cautions while handling, or using a conical flask are as follows;
- Before using the conical flask, it should be sterilized and wiped clean.
- After completing the experiment, the conical flask should be rinsed for 10 to 15 minutes with a warm detergent solution. Then, rinse it with tap water.
- A conical flask should be stored in a box in a dry location to prevent contamination.
- The conical flask should be handled carefully when in operation.
Differences between Conical Flasks and Beakers
Conical flasks and beakers are made of glass and essential laboratory equipment. However, both of them vary in features and applications;
- Conical flasks have a broad base and narrow neck. In contrast, beakers have flat bottoms, straight side walls, and a spout at the top.
- Because of the conical flask’s shape, it is better for mixing without spillage than beakers.
- Conical flasks with ground glass stoppers are available; air tightening makes it easier to store gaseous and other chemicals. On the other hand, beakers lack a cover, making them inappropriate for storing chemicals.
- The conical flask’s rounded and thin mouth makes pouring easier. However, the beaker’s top spout makes it simple to pour chemicals.
- Conical flasks are used for heating, storing, mixing, and performing chemical reactions. In contrast, beakers are used for careful mixing, measuring, and transporting liquids.
- The conical flask is used to filter various materials through a funnel because its narrow mouth supports the funnel. The beaker, on the other hand, is not suitable for filtration using a funnel due to its broad aperture.
- Erleynmeyer flask and filter flask: Pros, Cons, and Limitations. Lab Pro. Retrieved from https://labproinc.com/blogs/laboratory-equipment/erlenmeyer-flask-and-filter-flasks-pros-cons-and-limitations. Retrieved on 15th January 2023.
- Graduated Boro 3.3 Glass Eager Press Mouth Conical Flask. Superfit. Retrieved from https://www.superfitcare.com/Graduated-Boro-3-3-Glass-Eager-Press-Mouth-Conical-Flask-pd40063204.html. Retrieved on 12th January 2023.
- Flask. Retrieved from https://www.obrnutafaza.hr/pdf/scilabware/Flasks.pdf. Retrieved on 16th January 2023.