action of heat

On heating boric acid decomposes to form metaboric acid at 375 K, tetraboric acid at 435 K and boron trioxide at red heat...

When heated to 150C, magnesium sulphate heptahydrate changes to monohydrate, MgSO 4 .H 2 O, which at 200C gives anhydrous magnesium sulphate. On further heating, it is decomposed forming the oxide...

During initial heating of calcium sulphate dihydrate, the crystal structure changes. On further heating at 390 K, it loses water and forms CaSO 4 .5H 2 O or (CaSO 4 ) 2 .H 2 O. This is known at Plaster of Paris. On heating above 437 K, it becomes anhydrous CaSO 4 and..

When nitric acid or nitrates of metals other than sodium and potassium are heated, reddish brown fumes of nitrogen dioxide are produce..

Racemisation can be brought about by increasing the temperature. For e.g., lactic acid and amyl alcohol can give racemic mixtur..

Action of Heat on Sulphur - When heated, sulphur undergoes a series of characteristic changes. Sulphur can melt at two different temperatures. a) If heated rapidly, it melts at 112.8 o C. b) But if heated slowly it will melt only at 118.6 o C. Roll ..

Heat is a very powerful form of energy. Although there are other forms of energy like light and electricity, heat is the most commonly used agent for initiating all chemical changes. Various classes of substances undergo decomposition to various extents when heated. Th..

When carbon dioxide is passed over red-hot carbon in the form of coke charcoal, etc., the carbon dioxide loses one of its two atoms of oxygen. As a result, carbon dioxide gets reduced and becomes carbon monoxide. At the same time the hot carbon also gets converted to carbon monoxide (Fig.11.12). ..

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3 The precipitate of Al(OH) 3 is heated to a high temperature to obtain pure alumina. Thus, pure alumina is obtained from bauxit..