Question

For ochem

Rank the boiling point of water at these following three places. Explain why?

A) Deat Valley, Elevation -285 ft, P=1.01 atm

B) New York City, Elevation 0 ft, P=1.00 atm

c) Laramie, WY, Elevation 7165 ft, P=0.75 atm

In column chromatography. what would happen if the elution solvent is too polar?

Answer 1

From the information given in question, we can calculate the boiling point of water at different elevation (height),and at different atmoshpheric pressure. we know that as going from sea level to the height the atmoshpheric pressure gets reduced, as the atmoshtheric pressure reduces, it reduces the boiling point and as the atm. pressure increases boiling point increases.

A) Deat valley , given elevation is -285 ft, and atm. pressure =1.01 , means atmoshpheric pressure has raised , means boiling point of water should be greater than 100 ⁰C.

B) New York city, given elevation is 0 ft and at 1 atm, means boiling point of water is constant= 100⁰C.

C) Laramie, WY, Elevation 7165 ft,and 0.75 atm, here at this height pressure has reduced to.75 atm from 1 atm, means boiling point of water also reduced ( less than 100 deg c)

Rank of boiling point of the cities A>B>C

In coloumn chromatography, the polar solvents elute the polar compounds first from the coloumn, if elution solvent is too polar then the solvent will moves faster and generally there will not be good sepration, there fore selection of proper sovlent (molibe phase) is important to get the sepration of compounds.