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.

¶ 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.

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.
KH is Henry's law constant .

¶  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
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



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

How to Effectively Answer CBSE Board Examination Question Papers

The intend of this article is to share the best ways to answer the CBSE Board Examination. Usually most of the students tend to become nervous at the times of the board examination. In this article we will share the most effective ways to make the answers to the CBSE...

BRICS International Online Mathematics Competition

BRICSMATH.COM is an annual International Online Competition in Mathematics, for students of classes I – XII of 07 BRICS countries (Brazil, Russia, India, China and South Africa, Indonesia and Vietnam). The competition is held online on the website and...

Digital Marks Sheets Migration Certificates and Pass Certificates

CBSE pioneered in providing digital academic documents through its academic repository called “Parinam Manjusha” and DigiLocker.  As on now result data from 2004 till this year is available in the repository.  Approx. 12 crores digital academic documents are available...

Tricks for Utilization of additional time introduced in CBSE Board Exams

Tricks for Proper Utilization of Add-On 15 Minutes introduced in CBSE Board Exams The intend of this article is to share the best suggestions and guidelines to utilize the extra 15 minutes provided for reading the question paper in CBSE Board Examination. These extra...

Celebration of Republic Day by CBSE

As you are aware, Republic Day is celebrated every year on 26th January to honour the Constitution and Republic of our country. Celebration of this occasion annually helps youth and children of our country to be aware of the significance of Indian Constitution, unity...

Studies Today