Important: Safety Warning
This page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
Acetic Acid
This is the wellspecific gravity of 1.047. Special methods for testing the strength of acetic acid are given under Acetimetry, No 69. With bases this acid forms ACETATES.
Commercial acetic acid is principally manufactured on the large scale from acetate of soda, which yields a sufficiently strong and pure acid for commercial purposes, without the trouble of rectification. In this process, shallow copper vessels formed without rivets or solder in those parts exposed to the action of the acid, are employed for the purpose of the distillation. A coil of drawn copper pipe, heated by steam, having a pressure of 30 to known acid principle of vinegar. It is one of 35 pounds to the inch, traverses the bottom of the common products of fermentation, of the the apparatus. The refrigeratory consists of oxygenation of alcohol, and of the destructive well cooled earthenware vessels, and the adopter or pipe connecting the still with the of sulphuric acid and water, and, when cold, receivers is also of the same materials. Stills pour it on the acetate and sulphate, previously of earthenware are also frequently employed, placed in a retort; then distill to dryness in and even worms and condensers of silver are a sand bath. The acid that comes over in sometimes used. The crystalline acetate of the distillation by this process is very pure, and soda is placed in the still, and 35 to 36 parts may be used as a test acid for chemical anof strong oil of vitriol are added to every 100 alyses. parts of the acetate of soda, and the whole 3894. To Obtain Anhydrous Acetic stirred together with a wooden spatula. The Acid. This is acetic acid free from water, head of the still is then luted on and the dis- as it exists in dry acetates. Mix, in a glass tillation commenced. This produces an acid retort, well-fused acetate of potassa with half of a specific gravity of about 1.050, and, after its weight of chloride of benzoyle; apply a being agitated with a little animal charcoal, gentle heat, collect the liquid that distills and passed through a prepared muslin filter, is ready for sale. Some manufacturers add a little acetic ether to it. By this process 4 pounds of acetic acid of the strength above mentioned is obtained for every 3 pounds of the acetate of soda employed. (See No. 1741.)