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In Sandmeyer's reaction, replacement of the diazonium group by iodine is achieved by simply shaking the diazonium salt with:
The context mentions: 'Replacement of the diazonium group by iodine does not require the presence of cuprous halide and is done simply by shaking the diazonium salt with potassium iodide.'
Why are the methods for preparing alkyl halides from alcohols NOT applicable for the preparation of aryl halides from phenols?
The context explicitly states: 'The above methods are not applicable for the preparation of aryl halides because the carbon-oxygen bond in phenols has a partial double bond character and is difficult to break being stronger than a single bond.'
When an alkene reacts with hydrogen bromide (HBr), following Markovnikov's rule, which product predominates?
The context mentions: 'Propene yields two products, however only one predominates as per Markovnikov’s rule.' (Unit 13, Class XI), which implies that the halogen adds to the carbon atom of the double bond that has the greater number of alkyl substituents (or fewer hydrogen atoms).
A laboratory test for the detection of double bonds in a molecule involves the addition of bromine in $CCl_4$. What observation confirms the presence of a double bond?
The context describes: 'addition of bromine in CCl4 to an alkene resulting in discharge of reddish brown colour of bromine constitutes an important method for the detection of double bond in a molecule.'
Which of the following derivatives of ammonia contains a secondary amino group and is used to increase blood pressure?
The context states: 'Two biologically active compounds, namely adrenaline and ephedrine, both containing secondary amino group, are used to increase blood pressure.' Novocain is an anesthetic, Benadryl is an antihistaminic with a tertiary amino group, and quaternary ammonium salts are surfactants.
The geometry of amines is pyramidal, and the hybridization of the nitrogen atom in amines is:
The NCERT text explicitly mentions: 'Like ammonia, nitrogen atom of amines is trivalent and carries an unshared pair of electrons. Nitrogen orbitals in amines are therefore, $sp^3$ hybridised and the geometry of amines is pyramidal.'
Which of the following statements is INCORRECT regarding amines?
The context states: 'On the other hand, aromatic amines are weaker bases than ammonia due to the electron withdrawing nature of the aryl group.' The other options are correctly stated in the provided text.
Arrange the following amines in decreasing order of their boiling points, assuming similar molar masses: Primary amine, Tertiary amine, Secondary amine.
The text states: 'Therefore, the order of boiling points of isomeric amines is as follows: Primary > Secondary > Tertiary.' This is due to the extent of intermolecular hydrogen bonding, being highest in primary amines and absent in tertiary amines.
Why do primary amines have a higher boiling point than tertiary amines of comparable molar masses?
The text explains: 'This intermolecular association is more in primary amines than in secondary amines as there are two hydrogen atoms available for hydrogen bond formation in it. Tertiary amines do not have intermolecular association due to the absence of hydrogen atom available for hydrogen bond formation.'
Which method is preferred for the reduction of nitro compounds to amines, especially considering the regeneration of HCl?
The context mentions: 'Reduction with iron scrap and hydrochloric acid is preferred because $FeCl_2$ formed gets hydrolysed to release hydrochloric acid during the reaction. Thus, only a small amount of hydrochloric acid is required to initiate the reaction.'
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