Question

calculate the boiling temperatures of water and methanol when 1 atm reduces the pressure by 10 mm Hg

Answer 1

As we know Boiling point is characteristic physical property of a substance which depends upon external atmoshparic pressure

At sea level Pext=760 mmof hg so B.P of water is 373 K

But when Pext= 760-10= 750 mmof hug

Then B.P can be calculate by using Charles law

P1/T1= P2/T2

760/373= 750/T

So T=368K or 95degree celcius

Same for methanol B.P of methanol = 337.7 K

Now P1/T1=P2/T2

760/337.7=750/T

T=333.25K

Note. In question it is not clearly written that it is the solution of methanol and water or they are in isolated form

.mixture of Methanol and water is a positive deviated non ideal solution in case of their solution BP of solution must be less then the B.p of Water & calculation can be done by using formulas of colligative properties