To separate a mixture of p-toluidine and p-nitrotoluene dissolved in ether: a. extract the ether solution with aqueous HCl and treat the water layer with aqueous NaOH.
b. extract the ether solution with aqueous NaOH and treat the water layer with aqueous HCl.
c. extract the ether solution with water and treat the water layer with aqueous NaOH.
d. extract the ether layer with aqueous HCl and treat the ether layer with aqueous NaOH.
e. extract the ether solution with aqueous HCl and treat the ether layer with aqueous HCl.

extract the ether solution with aqueous HCl and treat the water layer with aqueous NaOH.

Explanation:

p-toluidine is a basic compound, it can react with aqueous HCl to form p-Toluidine hydrochloride and is recovered subsequently.

An alkali such as NaOH can be used to recover the p-toluidine. The neutral compound, p-nitrotoluene, will remain in the ether layer and can be recovered by evaporating the solution.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

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