A gas when mixed with oxygen, it produces a very hot and early controllable flame. What is the name of the flame and where is it used?

The number of geometrical isomers of butene are 

How many isomers has the organic compound represented by the formula C\(_3\)H\(_8\)O ?

When a few drops of Millon reagents is added to egg-white solution in a test tube, the white precipitate changes to

If the solubility of KNO\(_3\) at 30\(^0\)C is 3.10 mol/dm\(^3\) a solution containing 303g/dm\(^3\) KNO\(_3\) is likely to be