1.
If a sample of recently prepared 1-bromobutane is washed successively with water, cold
concentrated sulfuric acid, and then very dilute (5%) aqueous sodium bicarbonate solution, tell
which layer is 1-bromobutane in each of the 3 washings.
Solution
For each of the washing, there will be a different distribution of layer. Now layer distribution is
dependent on the density of the liquid. Because we know that, density = mass/volume, thus for a
similar volume, one having more density has a higher mass and the higher mass refers to the
bottom position in a container due to gravitational force (W = mg).
Now the densities of these liquids are:
1) 1-bromobutane = 1.2676 g.mL
2) Concentrated sulfuric acid = 1.84 g/mL
3) 5% aqs. sodium bicarbonate = 2.20 g/mL
4) water = 1 g/mL.
Now in water-1-bromobutane, the upper layer is water and the bottom layer is 1-bromobutane, in
sulfuric acid-1-bromobutane, the bottom layer is sulfuric acid and the upper layer is 1-
bromobutane, and in sodium bicarbonate-1-bromobutane, the bottom layer is sodium bicarbonate
and the upper is 1-bromobutane.
I hope it helps!!!!!!!!!