Kjeldahl Flask, 300mL - Long Neck, Round Bottom - Borosilicate Glass

This 300mL Kjeldahl flask is made from borosilicate glass and has a long neck, a round bottom, and a plain neck and no ground joint. It conforms to DIN ISO 12360 for nitrogen determination by the Kjeldahl method. The elongated neck holds acid vapor away from the mouth of the flask during digestion and returns condensate to the bulb, which allows the sample to be heated vigorously without loss. The round bottom distributes heat evenly across a mantle or burner instead of concentrating it at a flat base. The flask measures 11.8 inches tall overall, with a neck 8 inches long and 1.2 inches in diameter and a round bottom 3 inches in diameter. Borosilicate glass provides the chemical and thermal resistance the method requires, since Kjeldahl digestion holds concentrated sulfuric acid at high temperature for extended periods. The flask is autoclavable, with a strain point of 515°C, an annealing point of 565°C, and a softening point of 820°C.