How was CBSE Science Exam for Class X?

The preliminary examination of the All India P...

CBSE Science exam was today (20 March 2012).

How was the exam?

Many students reported that the exam was quite easy and could easily score 90% and above.

How was the Science exam for you?

Were there any errors in the question paper?

Were there any question out of syllabus?

Were the diagrams and other questions the expected ones?

Were there any questions beyond comprehension?

Respond now….

You can post the difficult and confusing questions as comments to this post and we’ll discuss the solutions

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Class XI CBSE Chemistry Model Paper


Class – XI

Time – 3 Hrs. Marks – 70


General Instructions :

i) All questions are compulsory.

ii) Q. s 1 to 8 carry 1 makes each. Answer them in one word or in about on sentence.

iii) Q. s 9 to 18 carry 2 marks each. Answer these in about 30 words each.

iv) Q. s 19 to 27 carry 3 marks each. Answer these in about 40 words each.

v) Q. s 28 to 30 are long answer questions carrying 5 marks each.

vi) Use long table if necessary, use of calculator is not permitted.


1. Write IUPAC name of the following compound : 1


2. Write down the formula of the monomer of silicone. 1

3. What would be the effect of increasing pressure on the equilibrium. 1

PCl5 (g) = Pcl3 (g) + Cl2 (g) ?

4. What is the oxidation number of oxygen in Na2O2 ? 1

5. What would be the sign of S for the process 2H (g) à H2 (g) ? 1

6. What is compressibility factor of a gas ? 1

7. Configuration of ion M+2 is Is2 2s2 2p5 what is configuration of atom M? 1

8. How many oxygen atoms would be there in 1 mole of H2SO4 ?

9. clip_image004 a) What is the hybridization of each carbon in CH3 – CH2 ? 1

b) What is the function of AlCl3 (anhyd) in Friedel Crafts reaction ? 1

10. How N and S are detected when present in an organic compound together ? (Reaction only) 2


Which is the electrophillic centre in CH3Br and why ?

11. Why lithium does not form a superoxide but potassium does ? 2


Why BeSO4 is water soluble but BaSO4 is not ?

12. Balance the following redox feaction by ion 2

Electron method :

Cr2 O7-2 + Fe+2 à Fe+3 + Cr+3 in acidic medium.

13. a) What is the change in internal energy in a process in which 700J of heat is absorbed and 450J of work is done by the system ?

b) Define a spontaneous process in terms of Gibbs energy. 1

14. Show by MO concept which one out of O2 and O2+ would be more stable. 2


Explain all the orbital overlaps in a molecule of ethene (C2H4) by drawing a sutitable diagram.

15. Calculate the mass of (NH4)2 S required to prepare 200 ml of O.1 molar aqueous solution.

(N = 14, H = 1, S = 32)

16. a) Write down the IUPAC name and symbol of the element with at no 119. 1

b) Why Cl has more negative electron gain enthalpy then F in group 17 ? 1

17. Arrange the species : F, O-2, N-3, Mg + 2, Al + 3 and Na+ in the increasing order of ionic radii and give reason. 2

Class 10 CBSE Science Summative Assessment II

Download A Model Question paper for Class 10 CBSE Science Summative Assessment II


Click here to Download the Marking Scheme

Must Practice Questions for CBSE Physics CLASS 12: Solved

We will publish here the portions one cannot afford to miss while preparing for the CBSE class 12  Physics Examination

The Chapters will be posted below. On Clicking the name of the chapter a new page will open. On that page there will be a set of collected questions. On clicking the questions, the complete solution to the questions will open.

Please note that this system is under preparation. We hope to complete this within a month. The link will be activated only after completing the project.



Fake Examination Boards Alert

CBSE has published a list of fake Examination Boards

  1. All India Board of Secondary Education, Ghazipur, Delhi
  2. Board of Adult Education
  3. Central Board of Higher Education, Vachaspati Bhavan,Uttam Nagar, New Delhi
  4. Board of Adult Education and Training, RS – 295 Brahampuri, Nangal Rai, New Delhi

If you come across any such Boards, you can inform them to the vigilance cell of CBSE or to Police

Educational News Update

Visa Relief To Tri Valley University’s Students In US

Responding to India’s strong reaction to how US authorities have been treating Indian students enrolled at the ‘sham’ Tri-Valley University in California, the US Immigration and Customs Enforcement (ICE) hinted that it would reinstate the visas of victimized Indian students through the I-539 form. I-539 form is used by the US Citizenship and Immigration Services (USCIS) to extend the visas and change immigration status of foreign nationals visiting the US. However, the request for visa extension or change of immigration status will only be considered on a case by case basis.


B-schools Plan Legal Action To Seek Reprieve From New AICTE guidelines

Over 200 management institutes across India are in discussions to approach the Delhi or Bombay High Court as a consortium and seek reprieve from recent guidelines issued by the All-India Council for Technical Education (AICTE). Among other things, AICTE had asked for common entrance tests for all PGDM programmes across the institutes, not to start admission process before March 31 in any academic year, and the institutes to seek approval of their course from their state panel.


Post-Study Employment Curbs In The UK Can Hit Number Of Indian Students Going There For MBA

In the wake of growing unemployment in Britain, the UK government abolished the visa that allowed Indian and non-EU students to work in the UK for two years after the completion of their courses. However, the London-based Association of MBAs holds a view that the move will hit the number of international students from India and elsewhere enrolling for MBA in the country. India and China are the biggest markets for international students for the UK and restricting their access to jobs market after studies can threaten future viability of the business education industry. MBA courses have high fees and international students are a good source of income for UK universities struggling for funding.


US Varsities Assessing Asian Aspirants Holistically; Reducing Focus on Test Scores

US universities are now judging higher education aspirants from India and Asia more holistically and trying to reduce their dependence on entrance test scores such as SAT, GMAT and GRE. They are also taking exceptional credentials of the student, their professional experience, insightful essays, social work and industry contacts into account while accepting students into their academic programmes.


CBSE To Offer Courses In Media, Films, Geospatial Studies, And Hospitality

After the huge success of introducing vocational courses during the last session, the Central Board of Secondary Education (CBSE) is all set to introduce courses in media, films, geospatial studies and food & beverages in 11,000 schools in India and abroad affiliated to it. The courses will be introduced in class XI from the academic session 2010-11 on pilot basis.