Q1.
two immiscible liquids of the same density are mixed in a separating funnel, how will the layers form?
Answer
They will not form two clean layers one above the other, and a separating funnel will fail to separate them.
Why it happens: A separating funnel works only because gravity acts more strongly on the denser liquid, pushing the lighter one up. If the two densities are equal, there is no net upward or downward push on either liquid — neither has any reason to float or to sink. The droplets of one liquid stay scattered through the other, so the mixture stays cloudy for a very long time and, if it does eventually settle, the boundary is blurred and its position is unpredictable. The liquids still do not mix (they remain immiscible and form separate droplets), but they no longer stack.
What could be done instead:
- Centrifugation — spinning the tube produces a force many times stronger than gravity, and even a very small density difference is then enough to drive one liquid outwards.
- Change one density — for example, dissolve a salt in the aqueous layer to make it denser, so the two separate normally.
- Distillation, if the two liquids have sufficiently different boiling points, since that method does not depend on density at all.