The label on a cooking oil pack says one litre (910 g). If this oil is mixed with water, will it form a separate layer? If so, which substance will be on top? How will you separate the two layers? Also, draw the diagram of the apparatus used.

Yes, cooking oil and water will form two separate layers because they are immiscible liquids, meaning they do not mix with each other. The oil will form the upper layer because 1 litre of oil has a mass of 910 g, so its density is 0.91 g/mL, which is less than the density of water.

The two layers can be separated using a separating funnel. This method works on the principle that immiscible liquids of different densities form separate layers. The mixture is poured into the separating funnel and left undisturbed until the two layers become clear. The stopcock is then opened slowly to drain out the lower layer of water into a beaker. Once the water is completely drained, the stopcock is closed, and the oil is collected separately in another container.