Q. Animal waste, oil and urea are some of the organic impurities present in sewage. Name two more organic impurities present in sewage.
Q. Explain the economic and social conditions of Russia before the Revolution of 1905.            Or State any three major effects of the First World War in Germany.
Q. What is yellow ammonium sulphide? Why is yellow ammonium sulphide and not ordinary ammonium sulphide used for the separation of IIA and IIB sub – group?