JEE Main 2022 · 26 July · morning · Single correct · +4 / −1
Refining using liquation method is the most suitable for metals with :
- (a) Low melting point
- (b) High boiling point
- (c) High electrical conductivity
- (d) Less tendency to be soluble in melts than impurities
Answer and solution
Answer (a) Low melting point
Solution
Chemistry ma’am · 4 steps
Liquation lets the metal melt and run off, so it needs a metal that melts well before its impurities do.
- What liquation does. The impure metal is placed on the upper end of a sloping hearth and heated gently. The metal melts and flows down, while the impurities stay behind as solid dross.
- Condition needed. This works only if the metal melts at a low temperature and the impurities do not melt at that temperature (they are infusible). The separation is solid versus liquid.
- Typical examples. Tin, lead and bismuth have low melting points, so they are refined by liquation.
- So. Liquation suits metals with a low melting point, which is option (a).
The idea to keep. Match the method to the property: low melting point means liquation, low boiling point means distillation, and impurities more soluble in the melt than in the solid means zone refining.
Answer from the NTA final answer key. Solution by PrepWiser.