What type of compounds can be seen in the acid-soluble fraction?

Step-by-step solution

One weighs a small amount of a living tissue (say a leaf or liver and this is called wet weight) and dry it. All the water, evaporates. The remaining material gives dry weight. Now if the tissue is fully burnt, all the carbon compounds are oxidised to gaseous form (CO2 , water vapour) and are removed. What is remaining is called ‘ash’. This ash contains inorganic elements (like calcium, magnesium etc). The inorganic compounds such as sulphate and phosphate can be seen in the acid-soluble fraction.