Solutions Flashcards
The elevation in boiling pt. of a solution of molal concentration of solute will be maximum if the solvent is
Chloroform
Solutions of similar osmotic pressure are known as
Isotonic
Benzene- chloroform DO NOT show ______ deviation from Raoult’s Law
positive
on dissolving common salt in water , the boiling point of water
Increases
When blood cells are kept in high osmotic pressure solution than cellsap then
, they shrink as the water moves from the cell (low concentration) to the outside (high concentration) This shrinkage of cells is called ‘‘plasmolysis’’
According to Raoult’s law , relative lowering of vapour pressure of solution of non volatile solute is equal to
Mole fraction of solute
For osmotic Pressure (P) volume (V) and temp. (T) which of the following statement is false if T is constant :
i) P proportional to 1/ V
ii) P proportional to T
iii) P proportional to V
iv) PV is constant
iii) P proportional to V is FALSE
An Ideal Soln is that which:
Obey’s Raoult’s Law
Formula for determining Osmotic pressure
= nRT / V
Ratio of observed value of colligative property to that of theoritical value is known as
van’t Hoff factor
Gram molality of a soln is
no. of molecules of solute per 1000 gm solvent
Semi permeable membrane is chemically
Copper ferrocyanide
in semiperemable membrane similar molar conc
Which among the following is a colligative property :
Surface tension
viscosity
osmotic pressure
optical inversion
Osmotic pressure
Order of osmotic pressure of BaCl2 , NaCl and glucose soln of same molarity will b
BaCl2 > NaCl > GLucose
True/False
Sum of Xa and Xb of a binary soln is more than unit
False
True/False
Molarity of a soln changes with temp.
True
True/False
All solns obey Raoult’s law
False
Magnitude of molal elevation constant adn molal depression constant are comparable
False
Berkley Hartley method cannot be used for the determination of osmotic pressure of non aqueous soln
False
Osmotic pressure of 1 M soln at 0* C is 22.4 atmosphere
True
Molarity (M) =
Molarity (M) = moles of solute/liters of solution
mol dm3
Molality (m) =
Molality (m) = moles of solute / kilograms of solvent.
mol/kg
Normality
Normality = Number of gram equivalents × [Volume of solution in litres]
An example of Soln of gas in liquid
Soda water
An example of Soln of solid in gas
Smoke
An example of non ideal soln showing positive deviation
CH3COCH3 + C6H6
An example of non ideal soln showing negative deviation
CHCL3 + CH3COCH3
At high altitudes the boiling point of water decreases because at high altitude atmospheric pressure is
Less
Through semi permeable membrane only _____ molecules can pass through
Solvent
Molality of water is
55.6 m
Liquid mixture which boil without any change in its composition is called
Azeotropic liquid mixture
Give an example of Anti-freeze compound
Ethylene glycol
Value of van’t hoff factor for a solute showing normal state in the soln will be ________ to one
Equal
Write the unit of representing pollution
ppm
What is Raoult’s law
At a definite temp. , for a soln of a non volatile solute the relative lowering in vapour pressure is equal to the mole fraction of solute
Formula of Van’t Hoff factor
i = Observed value of colligative property / calculated value of colligative propeerty
Define Molarity (M)
i) involves total volume of solution
ii) gram moles of solute are dissolved in 1 litre of soln
iii) it changes with temp. because volume changes with temp.
Define Molality (m)
i) involves mass of solvent
ii) gram moles of solute are dissolved in 1 kg of solvent. Here volume of soln is not considered
iii) it is independent of temp. as it takes mass into consideration
Define Solution
Solution is a homogenous mixture of 2 or more than 2 non reactive substances whose chemical composition can be varied within certain limits. Each soln contains two components solvent and solute
State Henry’s Law
According to this law, “The mass of a gas dissolved per unit volume of a solvent at constant temp. is proportional to the pressure of gas with which the solvent is in equilibrium.
Let in unit volume of solvent, mass of gas dissolved is ‘m’ and equilibrium pressure be P, then m proportional to P or m = KP where K is a constant
Define Mole fraction
Ratio of the moles of a component to the total no. of moles of all the components of soln is called mole fraction.
If moles of solute is n and that of solvent is N, then
Mole fraction of solute = n / (n + N)
Mole fraction of solvent = N / (n+N)
Define Ideal Soln
They obey Raoult’s Law
There is no change in enthalpy that takes place during the formation of solution
∆H mix= 0
There is no change in volume during the formation of solution
∆V mix = 0
Define non - Ideal Soln
Do not obey Raoult’s law
There is change in enthalpy that takes place during the formation of solution
∆H mix ≠ 0
There is change in volume during the formation of solution
∆V mix ≠ 0
Define Formality
The number of grams of formula masses of solute dissolved per litre of solution is known as the formality of a solution.
Formality = mass of ionic solvent in gm per ltr /
Formula mass of the solute
Define parts per million
ppm = mass of component A / total mass of soln x 10^6
ppm = volume of component A / total volume of soln x 10^6
What is Raoult’s Law
Raoult’s law states that a solvent’s partial vapour pressure in a solution (or mixture) is equal or identical to the vapour pressure of the pure solvent multiplied by its mole fraction in the solution.
Mathematically, Raoult’s law equation is written as:
Psolution = Χsolvent x Po solvent
Where,
Psolution = vapour pressure of the solution
Χsolvent = mole fraction of the solvent
Po solvent = vapour pressure of the pure solvent
Write about Positive deviation
Vapour pressure of soln and partial pressure of the components are more than those expected by the Raoult’s law.
∆H mix ≠ 0 and it is positive
∆V mix = positive
Forms minimum boiling azeotrope.
Write about negative deviation
Vapour pressure of soln and partial pressure of the components are less than those expected by the Raoult’s law.
∆H mix ≠ 0 and it is negative
∆V mix = negative
Forms maximum boiling azeotrope.
what is Semi permeable membrane
it is a membrane which allows the movement of a few solvent molecules through it. It appears to b continuous but it has very tiny holes or pores that are semi micro in nature. Through these only the molecules of solvent can pass while those of bigger size cannot pass through.
A soln contains 20 mole solute and total no. of moles is 80 . Mole fraction of solute will be :
0.25
Write the formula of molar conductance ʎm
k x v / M or k x 1000 / M
Why is CaCl2 used for clearing off snow from roads ?
it causes depression in freezing point so snow melts into liquid state. Water flows easily and roads get cleared.
HOW MANY ML OF 1 M H2SO4 IS REQUIRED TO NETURALIZE 10ML OF 1N NAOH
5 ML
MOLARITY OF SOLU OF H2SO4 CONTAINING 9.8GM H2SO4 DISSOLVED IN 2 L WATER
0.05
WHOSE BOILING POINT IS HIGHEST AT 1 ATM PRESSURE
1]0.1M GLUCOSE
2]0.1M BACL2
3]0.1 M NACL
4]0.1 UREA
2] 0.1 M BACL2
EXPERIMENTAL MOLECULAR MASS OF AN ELECTROLUTE WILL ALWAYS BE LESS THAN ITS CALCUTED VALUE BEACAUSE VALUR OF VANT HOFF FACTOR I IS EQUAL TO
MORE THAN 1
IN MOLAL SOLU 1 MOLE OF SOLUTE SUBSTANCE IS DISSOLVED IN
IN 1000GM SOLVENT
IF BOILING POINT OF SOLUTION IS T1 AND BOILING POINT OF SOLVENT IS T2 THEN ELEVATION IN BOILING POINT WILL BE
T1-T2
A SOLUTION CONTAINS 1 MOLE OF WATER AND 4 MOLES OF ETHANOL . THE MOLE FRACTION OF WATER ETHANOL IN SOLU WILL BE
0.2WATER+0.8ETHANOL
COLLIGATIVE PROPERTIES OF SOLU DEPANDS ON
NO OF SOLUTE PARTICLES PRESENT IN SOLU
OSMOTIC PROPERTIES FORMULA
⊓=NRT/V
6 GM UREA [MOL WT 60] DISSOLVED IN 180 GM OF WATER . THE MOLE FRACTION OF UREA WILL BE
0.1/10.1
NON IDEAL SOLU OF 95.4% OF H2O + C2H5OH REPRESENTS —- DEVIATION
+VE
WRITE EXAMPLE OF MINI. BOILING POINT CONSTANT SOLU
96.4% C2H5OH + 5% H2O
WHAT IS AZEOTROPIC MIXTURE ??
An azeotropic mixture is a mixture of substances that has the same concentration of vapour and fluid phases. A zeotropic mixture basically has constant or the same boiling points, and the mixture’s vapour will also have the same composition as the liquid.
TYPES OF AZEOTROPIC MIXTURE
- Minimum Boiling Azeotropes or Negative Azeotrope
Azeotropic mixtures with a higher boiling point in their constitutions are maximum boiling azeotropes. Water boils at 373 K, and hydrochloric acid boil at about 188 K, while azeotropes boil at around 383 K, - Maximum Boiling Azeotropes or Positive Azeotrope
Similarly, an azeotropic mixture that has a boiling point lesser than its constituents is known as a minimum boiling azeotrope. Consider, for example, ethanol consisting of a weight concentration of approximately ninety-five per cent and four per cent of water. Water boils at 373 K, and ethanol boils at about 351.5 K, while azeotropes boil at around 351.15 K
ISOTONIC SOLUTION
An isotonic solution is any external solution that has the same solute concentration and water concentration compared to body fluids. In an isotonic solution, no net movement of water will take place.
