Potassium hydroxide solutions heat capacity

Preparation of carbon monoxide from formic acid 50e A round-bottomed flask (capacity 1 1) is fitted by ground-glass joints with a dropping funnel and a gas-outlet tube, filled two-thirds full with concentrated phosphoric acid, and heated in a water-bath to 80° then formic acid is dropped in slowly. For removal of impurities (carbon dioxide, air, acid vapors, water vapor), the carbon monoxide evolved is passed successively through 50% potassium hydroxide solution and an alkaline solution of sodium dithionate (25 g of dithionate in 125 ml of water containing also 20 ml of 70% potassium hydroxide solution) and over potassium hydroxide, calcium chloride, and phosphoric oxide. 

Quite often Al, Fe, and Mg hydroxides partially fill the interlayer position of the derived vermiculites and decrease their exchange capacity and their ability to contract completely to 10 A when heated or when treated with a potassium solution. This material can usually be removed by treating the clay with a solution of sodium citrate (Tamura,1958). As the content of hydroxy interlayer material increases, the expandable clay tends to assume the character of a chlorite. Thus, in the weathering of a mica or illite it is not uncommon to form discrete vermiculite-like, beidellite-like, monf-morillonite-like and chlorite-like layers. These various layers can occur as discrete packets or interstratified in a wide variety of proportions. 

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