(iii) Racemisation takes place, i.e. True or False, The picture below is a resonance structure.

Question 50. Rearrange the compounds of each of the following sets in order of reactivity towards SN2 displacement : It is highly stable and not easily decomposed. Question 79: Since the new forces of attraction between water and alkyl halide molecules are weaker than the forces of attraction already existing between alkyl halide- alkyl halide molecules and water- water molecules, therefore, alkyl halides are immiscible with water.

reacts faster by SN1 mechanism as it is a tertiary halide and it produces a stable tertiary carbocation. BiologyMathsPhysicsChemistryNCERT Solutions, Kerala Syllabus 9th Standard Physics Solutions Guide, Kerala Syllabus 9th Standard Biology Solutions Guide.

(i) 2-Bromobutane (ii) 1, 3-Dibromobenzene (iii) 3-Chloroprop-l-ene. Question 54: %%EOF Write the structure of 2, 4-dinitrochlorobenzene. Explain why The first step involves formation of carbocation.

Write the structures of the following organic halogen compounds : (i) Preparation of 1-bromobutane from 1-butanol. Which one in the following pairs of substances undergoes SN2 substitution reaction faster and why? Answer: Haloalkanes and Haloarenes Previous Year Question 13:

Chlorine withdraws electrons through inductive effect and releases through resonance. Consider the thiocyanate (\(CNS^-\)) ion. 0000000016 00000 n Answer: Answer: The formal charge has to equal the molecule’s overall charge,e.g., the [latex] CNS^- [/latex] has an overall charge of -1, so the Lewis structure’s formal charge has to equal -1.

(i) p-Bromochlorobenzene, Question 56. Answer: Explain as to why (b) Why is methyl chloride hydrolysed more easily than chlorobenzene? following has, the highest dipole moment? Answer the following : The resonance hybrid for PO43–, hybrid bonds are in red. to Q.72 (iii). (b) Alkyl halides, though polar, are immiscible with water. 2. A more accurate description of the electron structure of the molecule requires considering multiple resonance structures simultaneously.

(b) Alkyl halides, though polar, are immiscible with water. (ii) (CH3)3 C – Cl or CH3 – Cl (All India 2014) Answer:

Resonance structures must also have the same amount of lone pairs. (ii) chlorobenzene is treated with Na metal in the presence of dry ether, What happens when C = 4 valence e–, N = 5 valence e–, S = 6 valence e–, also add an extra electron for the (-1) charge. Answer: Question 52.

Question 44. (iii) methyl chloride is treated with KNO2? Answer: Write the structure of l-Bromo-4-chlorobut-2-ene. (i) State one use each of DDT and iodoform. Question 9. Question 17. (ii) IUPAC name : 2-ethyl-l-nitrocyclohexane. Find the Lewis Structure of the molecule. 1, 4-dibromobut-2-ene. Write the chemical equations in support of your answer. (Delhi 2009) Six electrons are used to form three bonding pairs between the oxygen atoms and the carbon: 4. Have questions or comments? Answer: (ii) CH3—Cl is treated with KCN? (i) In haloalkanes, the halogen atom is attached Br (a) reacted with alcoholic KOH to give compound (b). This is due to greater electron density at these positions in resonance. In resonance structures, the electrons are able to move to help stabilize the molecule. Draw the structure of 2-bromopentane. Answer: Question 76. Resonance structures are used when a single Lewis structure cannot fully describe the bonding; the combination of possible resonance structures is defined as a resonance hybrid, which represents the overall delocalization of electrons within the molecule.

(a) (i) As I– ion is a good leaning group than Br, therefore reacts faster than CH3Br in SN2 reactions with -OH. In the following pair of compounds, which will react faster by SN1 mechanism and why? (i) Identify chiral in CH3CHOHCH2CH3 and CH3CHOHCH3. YES. Answer: Question 79. (ii) It is because the Grignard reagent reacts with water to form alkane, therefore, should be prepared in absence of water, i.e. IUPAC name : 3-bro?no-2-methyl propene. Answer: (i) CH2 = CHCH2 – Br Tertiary halides follow SN1 mechanism. Delhi 2013) Remember to determine the number of valence electron each atom has before assigning Formal Charges. Answer: Answer the following:

(ii) ethyl chloride is treated with AgN02, (ii) haloalkanes are only slightly soluble in water but dissolve easily in organic solvents.

Answer: Although chlorine is an electron withdrawing group, yet it is ortho-, para¬directing in electrophilic aromatic substitution reactions. Delhi 2017) Therefore, the sp2-hybrid carbon of C – Cl bond in chlorobenzene has less tendency to release electrons to Cl than a sp3 hybrid carbon of cyclohexyl chloride. (Delhi 2011)

B If the 6 remaining electrons are uniformly distributed pairwise on alternate carbon atoms, we obtain the following: Three carbon atoms now have an octet configuration and a formal charge of −1, while three carbon atoms have only 6 electrons and a formal charge of +1. The Hybrid Resonance forms show the different Lewis structures with the electron been delocalized.