Question

2) For a mixture of 20 mL diethyl ether and of 5% sodium hydroxide in 20 mL water two layers form. Based on densities, which layer is on the bottom? (3) Which layer will 4-nitrobenzoic acid be in. (4) Which layer will 4-nitrotoluene be in?
  

Answer 1

ether is less densier than water

so ether layer is top layer and aq. NAOH layer is bottom layer.

since NaOH is a strong base it reacts with 4-nitrobenzoic acid and form sodium salt of 4-nitrobenzoic acid, which is more solble in aq. layer.

so 4-nitrobenzoic acid goes to aq. NaOH layer.

and 4-nitrotoluene goes to ether layer