NEB important questions

Grade :12 Chemistry FM:75 PM:30 Author : NEB important questions Time:3 hours Group : “A” Attempt any 15 questions.(2*15 =30)
1)Define pH of a solution.Write relation between pH and pOH.
2)Mention one example of each :Trigonal and sp hybridization.
3)X gm of caustic soda requires 50 ml of 5 N HCl solution for complete neutralization.Find value of X.
4)Why is aqueous solution of Sodium carbonate basic?Explain.
5)Why is trichloroacetic acid stronger than chloroacetic acid?
6)Convert phenol to acetanalide.
7)Why does zinc become dull in moist air?
8)Define electrolytic conductance.Write its unit.
9)What happens when: a)Phenol is treated with chloroform and aq.NaOH. b)Chlororbenzene is heated with chloral in prescence of conc Sulphuric acid.
10)Suggest a chemical test to identify phenol and ethanol.
11)Show your familiarity with williamson's synthesis.
12)The half life of a first order reaction is 30 minutes.Calculate rate constant of the reaction.
13)Point out differences between end point and equivalence point.
14)Acetamaide is amphoteric in nature.Justify it.
15)Write the action of Heat and cobalt nitrate on zinc oxide.
16)Name two important ores of copper with formula.
17)Define heat of combustion and enthalpy of formation.
18)Give an example and use of homo polymer and co polymer.
19)What is an azodye?Give an example.
20)How can you say that life is impossible without Hydrogen bond?
21)What happens when oil is hydrogenated.
22)Convert calomel into corrosive sublimate and vice versa.

Group (B) Solve any 5 questions (5*5 =25)

23)An alkylhalide (X)when reacted with KCN gives a compound (Y),which on acidic hydrolysis gives a compound (Z).The compound Z reacts with calcium carbonate to produce a compound (A).The compound (A) when heated strongly gives propanone.Identify compound A, X,Y,Z.Give equations of all reactions.
24)How would you obtain primary,secondary,tertiary alcohols by using Grignard's reagent?Also state what happens when they are oxidized.( 3+2 )
25)Difference between Methanl and ethanal.
26)The standard reduction potential of copper and silver electrodes are +0.34V and +0.80 V respectively. a)Identify anode and cathode.(0.5+0.5) b)Calculate standard cell potential. (1) c)Write balance reaction taking at anode and cathode.(1) d)Write overall cell reaction.(1) e)Show it in figure.(1)
27)Describe the extraction of pure zinc from its sulphide ore.
28)State and explain the second law of thermodynamics.How does a free energy change depend on the equilibrium constant.
29)Define rate of reaction.Explain the effect of temperature and catalyst on the rate of reaction.

Group “C”

Solve any two questions. (2*10=20 )
30)How is pure aniline prepared in lab?Convert aniline into :a)Phenol b)phenyl isocyandie c)sulphanilic acid d)chlorobenzene
31)i)Starting from the ethanol how would you prepare the following? a)ethnae b)ethyl iodide c)ethyne d)ethanoic acid e)iodoform
ii)How is ethoxy ethane prepared in lab and purified ?
32)i)Define the terms : a)Acidimerity b)Formality c)Normality d)Molality e)Indicator
ii)3 g of trivalent metal was completely dissolved with 750 ml of 1N HCl.The residual solution further required 1000 ml of N/2 NaOH for the complete neutralization.Find the atomic mass of the metal.

iii)Calculate molarity of 5% Sulphuric acid solution.
33)Write short notes on any two : a)Manufacture of steel by open hearth process. b)Common ion effect c)lab preparation of methanoic acid. d)Chemistry on blue vitriol.

------The End------

Class 12: Biology

Section ‘A’ (Botany) – New Model

1. Answer any 7 very short questions. [1*7 = 7]
a. What is sclenchyma?

b. Define term diffusion.

c. What is phototropism?

d. What is heredity?

e. What is homozygous?

f. What is vegetative reproduction?

g. Define microsporogenesis.

h. What is self-pollentaion?

i. Define tissue culture.

j. What is antibiotic?

2. Answer any 5 questions in brief. [3*5 = 15]
a. Describe in detail about the types and functions of parenchymatous tissues.

b. Describe the uses of cytokinin.

c. Describe the structure of DNA.

d. Describe in detail about the incomplete dominance with example.

e. Describe the types of mutation.

f. Describe the process of double fertilization with necessary figures.

g. Discuss green manure and its application in agriculture.

3. Draw a well-labeled diagram of T.S. of dicot root and point out its differences with that monocot roots. [7.5]

OR
What is transpiration? Describe an experiment to show the unequal transpiration. [7.5]

4. Describe the s*x-linked inheritance with the reference of Drosophila (fruit fly). [8]

Section ‘B’ (Zoology)

1. Answer any 7 very short questions . [1*7 = 7]
a. Write full form of NADP.

b. Name the two s*x linked diseases in human.

c. What do you mean by myogenic heart?

d. What do you understand by Rh-factor?

e. In what form is oxygen transported to tissues?

f. Why is Hepatitis dangerous than AIDS.

g. Why blood group ‘A’ person cannot donate blood to blood group ‘B’ person.

h. Name the main steps of nutrition.

i. What is called brooding?

j. What is Toxoid? Give example.

2. Answer any 5 questions in brief. [3*5 = 15 ]
a. Describe the structure of areolar fissure.

b. Write notes on control measures of human population growth.

c. Discuss the fate of ectoderm.

d. Exchange of gases in the lungs.

e. Draw a L.S. of human eye.

f. What are heart sounds? How are they produced?

g. Explain the major causes of Cancer.

3. Give account of the process of urine formation in human being. [8]

OR

Explain the course of blood circulation in the human heart with the help of neat and well labeled diagram. [8]

4. Give an account of structure and function of a nephron in human being. [7.5]

HSEB QUESTION MODEL OF CHEMISTRY
GRADE : 11
FOR : 2070

Exam Oriented Model Question

Time : 3 hrs
Full Marks : 75
Pass Marks : 27
Group ‘A’
Attempt any Fifteen question : 15 X 2 = 30

Q.1. State Law of reciprocal proportion.
Q.2. The oxide of an element contains 67.67 % of oxygen and V.D. of its volatile chloride is 79
Q.3. Define surface tension of Liquid.
Q.4. Write down important differences between crystalline and amorphous solid.
Q.5. What is Pauli’s exclusion principle ?
Q.6. Give the values of all four quantum numbers of 11th electron of magnesium.(At. No. 12)
Q.7. What is radioactivity ?
Q.8. Write the Lewis structure of (a) H2O2 and (b) HNO3.
Q.9. Explain why HCL has polar character though it has covalent bond.
Q.10. State Modern Periodic law.
Q.11. How would you show the following reaction is a redox reaction?
Mg + Cl2 —————> MgCl2

Q.12. State Le-Chateliers principles.
Q.13. What are the difference between nascent and molecular hydrogen ?
Q.14. name any two oxides of each of the following :
(i) amphoteric
(ii) neutral.
Q.15 What is allotropy ? Name the latest discover allotropic form of carbon.
Q.16. What is meant by acid rain ? Give one major effect of acid rain.
Q.17. Distinguish between flux and slag with one example of each.
Q.18. Can sodium be extracted by the electrolysis of aqueous solutions of sodium chloride ? If not why ?
Q.19. Define electrophile and nucleophile with an example of each.
Q.20. Give IUPAC name of the following compound.
(a) CH3-CH(Br)-CH(NH2)-COOH
(b) CH3-C(CH3)2-C9OH)H-CH3
Q.21. What is meant by thermal cracking and catalytic cracking ?
Q.22. Identify A and B in the following reaction and give therir IUPAC name.
Cl2 alc.KOH
C2H6 ————-> A———————> B.
h v ∆
Group ‘B’

Attempt any five Question. 5 * 5 = 25

Q.23. Urea [(NH2)2CO] is prepared by reacting ammonia with carbon dioxide :
2NH3(g) + CO2(g) —–> (NH2)2CO(aq.) + H2O(l)
In one process, 637.2 g NH3 is treated with 1142g of CO2.
(a) Which of the following reactant is the limiting reactant ?
(b) Calculate the mass of urea formed
(c) How much excess reagent (in gram) is left at the end of the reaction ?
Q.24 State Avogadro’s law. Using the law to deduce relationship between Molecular mass and vapour density.
Q.25. State and explain Hund’s rule of maximum multiplicity.
Q.26. Specify Oxidation half, reduction half, oxidizing agent and reducing agent. Balance the following equation by ion-electron or oxidation number method :
Fe2+ + H+ + NO3– ——–> Fe+3 + NO + H2O
Q.27. Describe the manufacture of nitric acid by Ostwald’s process.
Q.28. Explain the laboratory preparation of carbon monoxide in laboratory What happens when CO is passed through finely divided nickel ?
Q.29. Describe the detection of foreign element (N,S,X) in organic compounds.
Group ‘C’

Attempt any two questions. : 2 X 10 = 20

Q.30.State Boyle’s law and Charles law. Derive PV=nRT. What is the density (in gram per liter) of ammonia at STP if the gas in a 1.0L bulb weights 0.672g at 25oC and 733.4 mm Hg pressure.
Q.31 Describe the manufacture of sodium carbonate by ammonia soda process. Also mention the function of limestone in the manufacture process.
Q.32. Write down the process involved in the manufacture of caustic soda by Solvay-Kellner’s process.

HSEB QUESTION MODEL OF CHEMISTRY
GRADE : 11
FOR : 2070

Exam Oriented Model Question

Time : 3 hrs
Full Marks : 75
Pass Marks : 27
Group ‘A’
Attempt any Fifteen question : 15 X 2 = 30

Q.1. State Law of reciprocal proportion.
Q.2. The oxide of an element contains 67.67 % of oxygen and V.D. of its volatile chloride is 79
Q.3. Define surface tension of Liquid.
Q.4. Write down important differences between crystalline and amorphous solid.
Q.5. What is Pauli’s exclusion principle ?
Q.6. Give the values of all four quantum numbers of 11th electron of magnesium.(At. No. 12)
Q.7. What is radioactivity ?
Q.8. Write the Lewis structure of (a) H2O2 and (b) HNO3.
Q.9. Explain why HCL has polar character though it has covalent bond.
Q.10. State Modern Periodic law.
Q.11. How would you show the following reaction is a redox reaction?
Mg + Cl2 —————> MgCl2

Q.12. State Le-Chateliers principles.
Q.13. What are the difference between nascent and molecular hydrogen ?
Q.14. name any two oxides of each of the following :
(i) amphoteric
(ii) neutral.
Q.15 What is allotropy ? Name the latest discover allotropic form of carbon.
Q.16. What is meant by acid rain ? Give one major effect of acid rain.
Q.17. Distinguish between flux and slag with one example of each.
Q.18. Can sodium be extracted by the electrolysis of aqueous solutions of sodium chloride ? If not why ?
Q.19. Define electrophile and nucleophile with an example of each.
Q.20. Give IUPAC name of the following compound.
(a) CH3-CH(Br)-CH(NH2)-COOH
(b) CH3-C(CH3)2-C9OH)H-CH3
Q.21. What is meant by thermal cracking and catalytic cracking ?
Q.22. Identify A and B in the following reaction and give therir IUPAC name.
Cl2 alc.KOH
C2H6 ————-> A———————> B.
h v ∆
Group ‘B’

Attempt any five Question. 5 * 5 = 25

Q.23. Urea [(NH2)2CO] is prepared by reacting ammonia with carbon dioxide :
2NH3(g) + CO2(g) —–> (NH2)2CO(aq.) + H2O(l)
In one process, 637.2 g NH3 is treated with 1142g of CO2.
(a) Which of the following reactant is the limiting reactant ?
(b) Calculate the mass of urea formed
(c) How much excess reagent (in gram) is left at the end of the reaction ?
Q.24 State Avogadro’s law. Using the law to deduce relationship between Molecular mass and vapour density.
Q.25. State and explain Hund’s rule of maximum multiplicity.
Q.26. Specify Oxidation half, reduction half, oxidizing agent and reducing agent. Balance the following equation by ion-electron or oxidation number method :
Fe2+ + H+ + NO3– ——–> Fe+3 + NO + H2O
Q.27. Describe the manufacture of nitric acid by Ostwald’s process.
Q.28. Explain the laboratory preparation of carbon monoxide in laboratory What happens when CO is passed through finely divided nickel ?
Q.29. Describe the detection of foreign element (N,S,X) in organic compounds.
Group ‘C’

Attempt any two questions. : 2 X 10 = 20

Q.30.State Boyle’s law and Charles law. Derive PV=nRT. What is the density (in gram per liter) of ammonia at STP if the gas in a 1.0L bulb weights 0.672g at 25oC and 733.4 mm Hg pressure.
Q.31 Describe the manufacture of sodium carbonate by ammonia soda process. Also mention the function of limestone in the manufacture process.
Q.32. Write down the process involved in the manufacture of caustic soda by Solvay-Kellner’s process.

Comment below if you need any help

Some of the Important Question that you mustn’t miss before the start of exam :

Unit 1 : VSEPR Theory
Unit 5 : Numerical Questions from this unit [5 marks, SQ]
Unit 6 : Gibbs Free Energy,….
Unit 7 : Numerical Question [Q. 30, 10 marks]
Unit 8 : Lab. Preparation of [Formic Acid] & [Anhydrous Methonoic Acid]
Unit 9 : Lab. Preparation of [Trichloromethane] & [Chloroform]
Unit 10 : Conversions || Victor Mayer’s Method
Unit 11 : Lab. Preparation of [Ethoxyethane or diethyl ether]
Unit 12 : Identification Type (if asked)
Unit 13 : Lab. Preparation of [Anhydrous formic acid]
Unit 14 : Lab. Preparation of [Nitrobenzene]
Unit 15: Hoffmann’s Method || Conversion (from Aniline) || Lab. Preparation [Aniline]
Unit 18: Extraction of Zinc || Chemistry of [White Vitriol] & [Zinc White]
Unit 18: Extraction of Mercury || Chemistry of Calomel
Unit 18: Manufacture of Steel by [Bessemer’s Process] & [Open-Hearth]
Some other Important Reactions:
Williamson’s Synthesis, Aldol, Cannizzaro’s Reaction, Perkin, Riemer-Tieman, Fidel craft Alkylation / Acylation, Fermentation, Sand Meyers

How does thermoelectric e.m.f varies with the temperature. Possible question for NEB 2074

NEB Targeted Questions For Physics.