Q1: The composition of fresh feed to the high temperature, high pressure urea autoclave is

ANS:B - excess liquid ammonia and compressed CO₂ gas.

The composition of fresh feed to the high temperature, high-pressure urea autoclave is excess liquid ammonia and compressed CO2 gas. In the synthesis of urea, the feedstock typically consists of liquid ammonia (NH3) and carbon dioxide (CO2). These two components are reacted under high temperature and high pressure conditions to produce urea. The process is often carried out in a urea synthesis reactor or autoclave. The ideal composition of the feed to the urea autoclave involves an excess of liquid ammonia (NH3) and compressed carbon dioxide (CO2) gas. This ensures that there are sufficient reactants present for the urea synthesis reaction to proceed efficiently. Therefore, the correct option is: excess liquid ammonia and compressed CO2 gas.