Question

why can we not separate sugar or salt mixed in water using filtration method.

Answer 1

Sugar and salt form a very fine solution. We know that filteration is a technique by which usually big suspended particles are used to remove from the solution or (the solvent).

Hence its better to use methods like distillation or fractional distillation for this tasks.

Answer 2

we cannot separate sugar or salt mixture in water because they make a very fine solution with water the particles are too small that they could pass through the pores of filter paper