Q1: Prilling tower is found in the flowsheet for the manufacture of

ANS:B - urea

A prilling tower is commonly found in the flowsheet for the manufacture of urea. In the production of urea, the prilling tower is used for the final step of the process, where the molten urea is sprayed or dripped from the top of the tower into droplets. As these droplets fall through the tower, they solidify into small spherical pellets or prills due to the cooling effect of air or a coolant flowing counter-currently in the tower. These prills are the final product of the urea manufacturing process and are then typically dried and cooled before being stored or transported. So, the correct answer is: urea Urea is a chemical compound with the chemical formula CO(NH2)2. It is one of the most widely used nitrogen-containing fertilizers in agriculture and is also used in various industrial applications. In agriculture, urea is a crucial source of nitrogen for plants. When applied to soil, urea undergoes hydrolysis, a chemical reaction catalyzed by the enzyme urease, to form ammonia and carbon dioxide: CO(NH2)2 + 2H2O → 2NH3 + CO2 The ammonia produced from this reaction serves as a nitrogen source for plants, aiding in their growth and development. Urea is favored as a fertilizer due to its high nitrogen content (typically around 46%) and relatively low cost compared to other nitrogen fertilizers. Apart from its use in agriculture, urea has numerous other applications. It is a common ingredient in skincare products and cosmetics, where it acts as a humectant, helping to retain moisture in the skin. In the pharmaceutical industry, urea is used in topical creams and ointments for its keratolytic properties, helping to soften and remove dry, rough skin. Additionally, urea is employed in the manufacturing of plastics, adhesives, resins, and as a component in certain chemical processes. Overall, urea plays a vital role in agriculture, industry, and healthcare, making it a versatile and indispensable compound in various sectors.