If the vapour pressure of
of water equals 0.03 atm (at 25°c), what is the vapour pressure of the solution which is produced from adding 5 mol of ethylene glycol to 1 l of water
at the same temperature
a 0.04 atm
b 0.027 atm
c 0.008 atm d 0.01 atm

b 0.027 atm

Explanation:

It is possible to solve this question using Raoult's law that says that the partial pressure of each component of an ideal mixture of liquids is equal to the vapour pressure of the pure component multiplied by its mole fraction in the mixture.

To know mole fraction of water you need to know how many moles of water have 1L. Moles are:

1L × (1000g/1L) × (1mol/18,01g) = 55,5 moles of water.

Mole fraction is:

55,5 moles of water / (55,5+5) total moles = 0,917

Thus, vapour pressure of the solution is:

0,917 × 0,03atm = 0,027atm

Right answer is:

b 0.027 atm

I hope it helps!

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-