CBSE Class 12 Chemistry Solutions Board Exam Notes

SOLUTION is the homogeneous mixture of two or more than two components. Most of the solutions are binary i.e. consists of two components out of which that is present in the largest quantity is called solvent & one which is present in smaller quantity called solute.
 
EXPRESSING CONCENTRATIONS OF SOLUTIONS

¶ Mass percentage: Mass of solute per 100g of solution Mass % = (mass of solute / total mass of solution) X 100
¶  Volume percentage : volume of solute per 100ml of solution Volume % = (volume of solute/ total volume of solution) X 100
 
¶  Parts per million: parts of a component per million (106) parts of the solution.
ppm = no. o f parts of the component / total no. of parts of all components of the sol. X 106
¶  Mole fraction(x): It is the ratio of no. of moles of one component to the total no. of all the components present in the solution . For binary solution :‐ the no. of moles of A and B are nA and nB respectively
so, xA= nA/nA+nB ; xB= nB/ nA+nB
In binary solution xA+ xB= 1
¶  Molarity: No. of moles of solute dissolved in one litre of solution .
Molarity(M) = moles of solute/ vol. of solution in litre
¶  Molality(m) : No. of moles of solute per kg of the solvent.
Molality(m) = moles of solute/mass of solvent in kg
Molality is independent of temp. whereas molarity is a function of temp. because vol. depends on temp. and mass does not.
 
HENRY'S LAW

It states that at a constant temp. the solubility of the gas in liquid is directly proportional to the pressure of the gas above the surface of the liquid .
It also states that the partial pressure (p) of a gas in vapour phase is proportional to the mole fraction of the gas (x) in the solution.
P=KHX
KH is Henry's law constant .
 
APPLICATION OF HENRY'S LAW

¶  To increase the solubility of CO2 in soda water and soft drinks the bottle is sealed under high pressure.
¶  To avoid bends , toxic effects of high concentration of nitrogen in the blood the tanks used Used by scuba divers are filled with air diluted with He.
 
RAOULT'S LAW :‐ it states that :
1) For a solution of volatile liquid , the partial vapour pressure of each component of the solution is directly proportional to its mole fraction present in solution.
PA= P0
A XA PB= P0B XB
The total pressure is equal to sum of partial pressure. Ptotal= PA+ PB
2) For a solution containing non‐volatile solute the vapour pressure of the solution is directly proportional to the mole fraction of the solvent.
 
 
Please click the link below to download pdf file of CBSE Class 12 Chemistry Solutions Board Exam Notes

Tags: 

 


Click to View or Download pdf file
Click for more Chemistry Study Material

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

CBSE Board Exams in July Press Release

CBSE has released press note for the dates for the CBSE Board exams for Class 10. CBSE said “With regards to conduct of Class X examinations several queries are being received by the CBSE. In this context, it is once again reiterated that remaining examinations of...

CBSE Online Training for Teachers 2020

It is clear that this pandemic has utterly disrupted an education system that many assert was already losing its relevance. Enhancing professional development digitally is a need in the times of COVID-19, where social distancing and remote interactions is the new...

Class 10 Board Exams to be held

The CBSE board has announced that there is no change in the decision of conducting the CBSE board exams for the 29 subjects, which were canceled due to coronavirus crisis. So when the lockdown gets relaxed completely, the board will conduct the exams for the students,...

Board Exams Class 10 and 12 Notification by CBSE

Because of the prevailing condition of spread of COVID-19 pandemic in the country, special efforts are required for conducting examinations in a safe manner. As a number of students have shifted from the district of their school to some other district in the country,...

CBSE advisory on student marks

CBSE has issued a public advisory for all students to be careful from unscrupulous persons impersonating themselves as officers/officials of CBSE. These people have been contacting parents and have been telling them that they have access to student marks data for Board...

CBSE Decision on Board Exam 2020

The Class 10 and 12 exams are cancelled, and results for both 10th and 12th would be declared by July 15 based on internal exams. CBSE Class 12 students would have the option to appear for the exams at a later date. CBSE has a scheme in which marks scored in past 3...

×
Studies Today