Q1: Dephosphorisation of molten pig iron is favoured by

ANS:B - reducing and basic slag.

Dephosphorisation of molten pig iron is favored by oxidizing and basic slag. Explanation:

• Phosphorus removal from molten pig iron is achieved by forming phosphorus-rich compounds with the slag phase.
• Oxidizing conditions are favorable because they promote the conversion of phosphorus in the metal to phosphorus oxide (P2O5), which then reacts with the basic components of the slag.
• Basic slag refers to a slag composition that contains a high proportion of basic oxides, such as calcium oxide (CaO) or magnesium oxide (MgO). These oxides react with phosphorus oxide to form phosphates, which are then removed from the molten metal into the slag.
• Reducing conditions would not favor the formation of phosphorus oxides, and neutral slag may not have sufficient basicity to efficiently capture phosphorus from the metal. Therefore, oxidizing and basic slag conditions are preferred for effective dephosphorisation.