Why is an organic compound fused with Sodium for testing nitrogen,halogens and sulphur ?

(a) : 3Na4[Fe(CN)6] + 4Fe3+  → Fe4 [Fe(CN)6]3 + 12Na+  Prussian blue

Nitric acid is added to decompose NaCN and Na2S   NaCN + HNO3 → NaNO3 + HCN   Na2S + 2HNO3 → 2NaNO3 + H2S  H2S and HCN are gases and are escaped from the...

Lead acetate on reacting with sulphuric acid will give a white ppt of lead sulphate which interferes in the detection of sulphur.   (CH3COO )2Pb + H2SO4 ----------> PbSO4 + 2CH3COOH

Because FeSO4 gets hydrolysed if its solution is stored for long.

Mass of the compound = 0.468 g  Mass of the barium sulphate = 0.668 g  % of sulphur = 32 X Mass of barium sulphate X 100/ 233 X Mass of the...

Volume of nitrogen collected at 300K and 715mm pressure is 50 mL  Actual pressure = 715-15 =700 mm  Volume of Nitrogen at STP=273*700*50/300*760  =41.9 ml  22400 ml of Nitrogen at STP weighs = 28...

Sodium extract is boiled with nitric acid to decompose NaCN and Na2S, if present, otherwise these NaCN + HNO3        NaNO3 + HCN Na2S + 2HNO3         ...

The organic compound is fused with sodium metal to convert these elements which are precent in the covalent form to ionic form

For testing sulphur, the sodium extract is acidified with acetic acid because lead acetate is soluble and does not interfere with the test. If H2SO4 were used, lead acetate itself...

Here, mass of the substance taken= 0.157g Mass of BaSO4 ppt. formed= 0.4813g 1 mole of BaSO4 is equivalent to 1 g atom of S (137+32+64)= 233g of BaSO4=32g of S 0.4813g of BaSO4...