DATE OF SUBMISSION 23-07-2018

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DATE OF SUBMISSION 12-11-2017

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DATE OF SUBMISSION 06-11-2017

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PERIODIC CLASSIFICATION OF ELEMENTS                        

1. State Mendeleevs periodic law .

2. What is law of octaves ?

3. What are the merits and demerits of Mendeleevs periodic table?

4. Define  a period and group in the periodic table.

5. Account for the following.

(i) Atomic radius increases from top to bottom in a group and decreases from left to right in a    period.

(ii) Ionization enthalpy decreases from top to bottom in a group and increases from left to right in a period.

(iii) First ionization enthalpy of Be is slightly higher than that of B.

(iv) First ionization enthalpy of N is higher than that of O.

(v) Electron gain enthalpy of F is less negative than that of Cl

(vi) The first member of each group differs from the properties of remaining elements of the same group.

(vii) Second ionization enthalpy is always greater than first IE.

(viii) d- block elements are called transition elements.

6. What is diagonal relationship?

7. How does metallic and nonmetallic character vary in the periodic table along a period and   in a group?

8. Write the general electronic configurations s,p,d and f block elements.

9. Write a short note on valency of elements.

10. What is the difference between electronegativity and electron gain enthalpy?

HYDROCARBONS

DATE OF SUBMISSION: 15.02.2016

1.       How will you effect the following  conversions?

i.                     Ethene to ethane

ii.                   Methane to ethane

iii.                   Propanoic acid to ethane

iv.                 Propyl chloride to propene

v.                   Ethyl alcohol to ethane

vi.                 Propene to 2-Bromopropane

vii.                Propene to 1-Bromopropane

viii.              2-Bromopropane to propene

ix.                  1-Bromopropane to 2-Bromopropane

x.                   2-Bromopropane to 1-Bromopropane

xi.                 Propene to propan-2-ol

xii.                1,2-Dibromoethane to ethane

2.       Explain with example.

i.                     Conformations in alkanes

ii.                   Β – elimination

iii.                  Markovnikovs rule

iv.                 Anti markovnikovs rule or kharash effect

v.                   Mechanism of Markovnikovs addition

3.       Write IUPAC names of the following.

i.                     CH₂ = CH CH(CH₃)CH₃

ii.                   CH₃ CH₂ CH₂O CH₂CH₃

HYDROCARBONS

HYDROCARBONS

1.       Write structures of different  chain isomers of  alkanes corresponding  to the molecular formula C₆H₁₄. Also write their IUPAC names.

2.       Write IUPAC names of the following compounds:

(i)                  (CH₃)₃ C CH₂ (CH₃)₃

(ii)                (CH₃)₂ C (C₂H₅)₂

(iii)               Tetra-tert-butylmethane

3.       Write the structural formulas of the following compounds:

(i)                  3,4,4,5 –tetramethylheptane

(ii)                2,5 –Dimethylhexane

4.       Sodium salt of which acid is needed for the preparation of propane? Write chemical equation for the reaction.

5.       Explain the mechanism of free radical  chlorination of methane.

6.       Explain the terms.

(i)                  Isomerisation

(ii)                Aromatization

(iii)               Pyrolysis  or cracking .

ORGANIC CHEMISTRY SOME BASIC CONCEPTS

CLASS XI   A & B                                                                           CHEMISTRY

HOME WORK   23/01/2017

ORGANIC CHEMISTRY SOME BASIC CONCEPTS

1.       What is the hybridization  state of each carbon atom in the following compounds?                              CH₂=C=O , CH₃ CH = CH₂ , (CH₃) ₂ CO , CH₂ = CH CN , C₆ H₆

2.       Write the bond line formulas for :

             isopropyl alcohol, 2,3-Dimethyl butanal,Heptan-4-one.

3.       Draw the formulas for the first five members of each homologous series beginning with the following compounds.

                    (a) H-COOH (b) CH₃COCH₃  (c) H-CH = CH2  

4.       Draw the resonance structures of the following compounds . Show the electron shift using curved arrow notation

             (a) C₆H₅OH (b) C₆H₅NO₂ (c) CH₃ CH = CH CHO (d) C₆H₅CHO.

5.       Explain the terms Inductive and electromeric effects.Which electron displacement effect explains the following correct orders of acidity of the carboxylic acids?

(a)    Cl₃ CCOOH > Cl₂CH COOH > ClCH₂COOH

(b)   CH₃ CH₂ COOH > (CH₃)₂ CH COOH > (CH₃)₃ C COOH 

6.       Give a brief description of the principles of the following techniques taking an example in each case.

(a)    Crystallization  (b) Distillation (c) Chromatography

7.       A sample of organic compound contains 69% C, 4.8% H and the remaining  oxygen. Calculate the masses of CO₂ and water produced when 0.20 g of this substance is  subjected to complete combustion.

8.       0.3780 g of an organic chloro compound gave 0.5740 g of silver chloride in Carius method. Calculate the percentage of chlorine present in the compound.

9.       In the estimation of S by carius method 0.468 g of an organic sulphur compound afforded 0.668 g of barium sulphate . Find out the percentage of S in the compound.

10.   Which of the following carbocation is most stable?

(a)    (CH₃)₃ C C⁺H₂  (b) (CH₃)₃ C⁺  (c) CH₃ CH₂ CH₂⁺ (d) CH3C⁺H CH₂ CH₃

11.   Explain hyperconjugation effect with example.

12.   Describe Lassaigne’s test for halogens, nitrogen and sulphur