Welcome to Chem Zipper.com......: November 2021

Search This Blog

Tuesday, November 23, 2021

Class Claperon equation:


Vapour pressure is directly proportional to the Temperature so that on increasing temperature the rate of evaporation increases and rate of condensation decreases and hence vapour pressure increases.
The dependence of vapour pressure and temperature is given by CLASIUS CLAPERON equation.

Related topics:

What is relation between equilibrium constant and activation energy ?

Monday, November 15, 2021

Liquid A and B forms an ideal solution and initial vapour pressure of A and B are P°A= 0.4 atm and P°A= 0.6 atm respectively. In a cylinder piston arrangement, 2 mole vapour of A and 3 mole vapour of B is collected at 0.42 atm.

(1) predict wheather the vapour will condense or not ?
(2) If the vapours are  compared slowly and isothermally at what  pressure F drop of liquid will form?
(3) If initial volume of vapour was 10 litre , at what volume first drop of liquid is form?
(4) What is the composition of first drop of liquid formed?
(5) If vapour pressure are further compressed. At what  pressure  almost complete condensation of vapour will occure?
(6) Determine the composition of last traces of vapours remains?
(7) What is the composition of system at 0.55 atm pressure?
(8) Determine the composition of liquid and vapour formed  at 0.51 atm also  calculate the moles of liquid of A and B in liquid and vapour formed ?
(9) At what pressure half of the total amount of vapour will condense?

Related Questions;







Sunday, November 14, 2021

Vapour pressure of a solution containing 6 gm of non volatile solute in 180 gm of water is 20 torr/mmHg. If 1 mole of water is further added in to the V.P. increases by 0.02 torr. calculate the V.P. of pure water and molecular wt of the non volatile solute.

10 gm of a solute is dissolved in 80 gm of acetone V.P. of solution is 271 mm Hg. If V.P. of pure acetone is 283 mm of Hg. calculate molar mass of solute.

calculate weight of urea which must be dissolved in 400 gm of water so that final has V.P. 2% than V.P. of pure water?

What is relation between relative lowering of vapour pressure and molality of solution?

ILLUSTRATION



Related Questions;

Saturday, November 13, 2021

200 ml of 0.2M urea solution is mixed with 200 ml of glucose solution at 300 K. Calculate osmotic pressure of resulting solution.


Related Questions;

Friday, November 12, 2021

How to determine total vapour pressure of solution in liquid phase as well as gas phase ?

According to Raoult's Law: The partial pressure of any volatile component of a solution at any temperature is equal to the vapour pressure of the pure component multiplied by the mole fraction of that component in the solution.
      Where XA­ and XB is the mole fraction of the component A and B in liquid phase respectively

According to Dalton's Law:
The vapour behaves like an ideal gas, then according to Dalton's law of partial pressures, the total pressure PTis given by:
 Partial pressure of the gas = Total pressure x Mole fraction
                                        PA = PT YA and PB =PT YB
Where YA­ and YB is the mole fraction of the component A and B in gas phase respectively
Combination of Raoult's and Dalton's Law:
(3) Thus, in case of ideal solution the vapour phase is phase is richer with more volatile component i.e., the one having relatively greater vapour pressure

Graph Between 1/YA Vs 1/XA:

According to Dalton's law of partial pressures, the total pressure PT is given by:
 Partial pressure of the gas = Total pressure x Mole fraction
Where YA­ and YB is the mole fraction of the component A and B in gas phase respectively
According to Raoult's law:
On rearrangement of this equation we get a straight line equation:

Illustrative Examples:

Wednesday, November 10, 2021

When a solution containing w of urea in 1kg of water is cooled to 272K, 200g of ice is separated. If for water is 1.86Kkgmol−1,w is:

Related Questions;

What is Azeotropic mixture or solution?

A solution which boils like a pure liquid and has same composition in liquid as well as vapour phase is called Azeotropic solution or mixture.
Features of Azeotropic mixture:
# For Azeotropic solution XA =YA
# An ideal solution can not form Azeotropic mixture.
# only non ideal solution form Azeotropic mixture.
# composition of Azeotrope alter on changing external pressure.
# Azeotropic solution can't separated by fractional distillation.
Type of Azeotropic solution or mixture:
(1) Minimum boiling Azeotropic solution
It is formed by solution which show positive (+) deviation from ideal behaviour. Such solution has boiling point smaller than boiling point of both of components liquids.
For example, mixture of 95% ethanol by weight and 4% of water. 
Water boils at 373 K, and ethanol boils at about 351.5K, while azeotropes mixture of both boil at around 351.15 K, suggesting a boiling point lower than its constituents.

(2) Maximum boiling Azeotropic solution.
It is formed by solution which show negative (-) deviation from ideal behaviour. Such solution has boiling point larger than boiling point of both of components liquids.
For example,  mixture of approximately 20% by weight hydrochloric acid and 79 % of water.
Water boils at 373 K and hydrochloric acid boil at about 188 K,  while azeotropes  of both boil at around 383 K which is a boiling point greater than its constituents.

Related Questions;