Download App

Organic Chemistry: Some Basic Principles and Techniques — Chemistry STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceChemistryOrganic Chemistry: Some Basic Principles and Techniques5 Marks
Question
  1. Write two important differences between inductive effect and resonance effect.
  2. Give reasons to explain the following observations:
  1. Carbon atom number 2 in CH3CH2Cl has more positive charge than that in CH3-CH2-Br.
  2. CH3-CH=CH-CH=CH2(I) is more stable than CH3-CH=CH-CH2-CH=CH2(II)
✓

Answer

  1.  
S. No
Inductive effect
Resonance effect
1.
It involves o electrons.
It involves $\pi-$ electrons or lone pair of electrons.
2.
It decreases with distance and vanishes after 4th carbon atom.
It is all along the length if system is conjugated (alternate double bonds).
3.
It is shown by even non-planar compounds.
It is shown by only planar compounds.
  1.  
  1. Polarisation of CH3CH2Cl and CH3CH2 Br can be shown as follows.

$\stackrel{\delta\delta+}{\text{CH}_3}-\stackrel{\delta+}{\text{CH}_2}-\stackrel{\delta-}{\text{Cl}}\ \ \ \ \ \ \ \ \stackrel{\delta\delta+}{\text{CH}_3}-\stackrel{\delta+}{\text{CH}_2}-\stackrel{\delta-}{\text{Br}}$

Chlorine is more electronegative than Bromine. C-Cl bond is more polar than C-Br bond. Hence, inductive effect of 'Cl' is greater on the second carbon than Br.

  1. Resonating structures of (I)

It is more stable due to resonance effect due to conjugation i.e., alternate double bonds than II in which there is no resonance due to absence of conjugation.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from Organic Chemistry: Some Basic Principles and Techniques→Organic Chemistry: Some Basic Principles and Techniques — all question types→Chemistry STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

  1. What is the total number of electrons in $\text{NO}^-_3$ and $\text{NH}^+_4?$
  2. Why is melting point of MgO (2800°C) higher than that of BaO (1920°C)?
  3. Why is solubility of MgCl, greater than that of MgF2?
  4. Why are carbon-oxygen bond lengths in Na2CO3 equal?
  5. Why is AlF3 high melting solid whereas SiF4 is a gas?
→
Define electronegativity. How it is different from electron gain enthalpy? Explain the periodic trend of electronegativity in periodic table.
→
Write the structure of important functional group and make a table of their prefixes and suffixes according to IUPAC.
→
  1. A beam of helium atoms move with a velocity of 2.0 × 103ms-1. Find the wavelength of the particle constituting the beam, (h = 6.626 × 10-34Js).
  2. An electron is moving with a kinetic energy of 2.275 × 10-25J. Calculate its de-Broglie wavelength. (Mass of electron = 9.1 × 10-31kg, h = 6.6 × 10-34Js)
→
Describe different types of thermodynamic equilibria.
→
Explain IUPAC system of nomenclature of elements with example.
→
Why was a change in the Bohr Model of atom required? Due to which important development (s), concept of movement of an electron in an orbit was replaced by, the concept of probability of finding electron in an orbital? What is the name given to the changed model of atom?
→
Explain the important aspects of resonance with reference to the $\text{CO}^{2-}_3$− ion.
→
Calculate (a) $\Delta \text{G}^\ominus$ (b) the equilibrium constant for the formation of NO2 from NO and O2 at 298K
$\text{NO (g) + }1/2\text{ O}_2\text{ (g)}\rightleftharpoons\text{NO}_2\text{ (g)}$
where
$\Delta_\text{r}\text{G}^\ominus\text{ (NO}_2)=52.0\text{ kJ/mol}$
$\Delta_\text{r}\text{G}^\ominus\text{ (NO})=87.0\text{ kJ/mol}$
$\Delta_\text{r}\text{G}^\ominus\text{ (O}_2)=0\text{ kJ/mol}$
→
Give the laws for IUPAC nomenclature of organic compounds have multiple groups and give examples.
→